MACROCYCLIC COMPOUNDS AND USES THEREOF CROSS-REFERENCE TO RELATED APPLICATIONS [0001] The present application claims priority to U.S. Provisional Application No. 63/410,823, filed on September 28, 2022, and which is hereby incorporated by reference in its entirety. FIELD OF THE INVENTION [0002] Described herein are macrocyclic compounds that can be used as kinase inhibitors. In particular, compounds described herein can inhibit epidermal growth factor receptor (EGFR), including mutant forms of EGFR. Compounds described herein can be effective for treating various disorders that include cancers such as EGFR-driven cancers (e.g., non-small cell lung cancer (NSCLC) characterized by mutant EGFR). BACKGROUND [0003] Signal transduction refers to the transmission of stimulatory or inhibitory signals into and within a cell leading, often via a cascade of signal transmission events, to a biological response within the cell. Defects in various components of signal transduction pathways have been found to account for a large number of diseases, including numerous forms of cancer, inflammatory disorders, metabolic disorders, vascular and neuronal diseases. [0004] Signal transduction is often mediated by certain proteins called kinases. Kinases can generally be classified into protein kinases and lipid kinases, and certain kinases exhibit dual specificities. For example, epidermal growth factor receptor (EGFR) belongs to a family of receptor tyrosine kinases (RTKs) that include EGFR/ERBB1, HER2/ERBB2/NEU, HER3/ERBB3, and HER4/ERBB4. The binding of a ligand, such as epidermal growth factor (EGF), induces a conformational change in EGFR that facilitates receptor homo- or heterodimer formation, leading to activation of EGFR tyrosine kinase activity. Activated EGFR then phosphorylates its substrates, resulting in activation of multiple downstream pathways within the cell, including the PI3K-AKT-mTOR pathway, which is involved in cell survival, and the RAS-RAF-MEK-ERK pathway, which is involved in cell proliferation. (Chong et al. Nature Med.2013;19(11):1389-1400). [0005] Certain cancers are characterized by mutations of EGFR, which results in increased cell proliferation. Tyrosine kinase inhibitor (TKI) therapies that inhibit EGFR can lead to clinical responses; however, mutations in EGFR can also confer resistance to such therapies. [0006] Further, one of the major pathways to regulate proteins post-translationally is ubiquitin-dependent proteolysis. The first step in selective degradation is the ligation of one or more ubiquitin molecules to a protein substrate. Ubiquitination occurs through the activity of ubiquitin-activating enzymes (E1), ubiquitin-conjugating enzymes (E2), and ubiquitin-protein ligases (E3), which act sequentially to catalyze the attachment of ubiquitin to lysine residues of substrate proteins (see Ciechanover A., et al., BioEssays, 22:442–451 (2000)). The E3 protein ligases confer specificity to ubiquitination reactions by binding directly to substrate. [0007] New therapeutic methods therefore remain necessary for treating cancers associated with defective signal transduction pathways, including EGFR-driven cancers and cancers which develop resistance to one or more therapies. SUMMARY OF THE INVENTION [0008] Described herein are new compounds that can be effective inhibitors of EGFR. Such compounds can be useful for treating various diseases and disorders, including EGFR-driven cancers such as non-small cell lung cancer (NSCLC) characterized by mutant EGFR. For example, the present compounds can be useful as proteolysis-targetic chimera (PROTAC) therapies for the treatment of mutant EGFR, including EGFR comprising one or more resistance mutations. [0009] In one aspect, the invention features a compound having a structure according to Formula (AI): or a pharmaceutically acceptable salt thereof, wherein: A is C _6-10 arylene, 5-12-membered heteroarylene, or 5-12-membered heterocycloalkylene; X ¹ is N or CR ^X ; X ² is N or CR ^X ; X ³ is N or CR ^X” ; X ⁴ is N or CR ^X” ; X ⁶ is N or CR ^X’ ; X ⁷ is N or CR ^X’ ; ------ represents an optional double bond between X ⁷ and X ⁴ or X ⁴ and X ⁶ , wherein one and only one double bond is present; X ⁵ is a covalent bond, CH ₂ , O, NR ⁴ , C(O)NR ⁴ , or NR ⁴ C(O); L ¹ is a covalent bond or C(R ⁵ ) ₂ , and L ² is C _1-4 alkylene, or L ¹ and L ² combine to form a C _3-6 cycloalkyl or a 4- to 6-membered heterocycloalkyl; R ¹ is –L ^P -E, halogen, C _1-6 alkyl, C _3-7 cycloalkyl, C _6-10 aryl, 5- to 10-membered heteroaryl, 3- to 10-membered heterocycloalkyl, CN, NR ⁶ R ⁷ , NR ⁶ C(O)R ⁷ , NR ⁶ C(O)NH ₂ , OR ⁸ , or C(O)NR ⁶ R ⁷ , and where valency permits when R ¹ is not –L ^P -E, R ¹ optionally further comprises -L ^P -E; R ² is absent, H, C _1-6 alkyl, halogen, CN, or C _1-6 alkoxy; each R ³ , when present, is independently OH, CN, halogen, C _1-6 alkyl, or C _1-6 alkoxy; n is 0, 1, or 2; each R ^X is independently H, OR ^X1 , CN, halogen, or C _1-6 alkyl, wherein R ^X1 is H or C _{1- 6} alkyl; each R ^X’ is independently H, OR ^X1 , CN, halogen, or C _1-6 alkyl, wherein R ^X1 is H or C _{1- 6} alkyl, or R ^X’ is absent if the carbon to which it is attached is part of a double bond; each R ^X” is independently –L ^P -E, H, OR ^X1 , CN, halogen, or C _1-6 alkyl optionally comprising -L ^P -E, and wherein R ^X1 is H or C _1-6 alkyl optionally comprising –L ^P -E; L ^P is a linker; E is an E3 ubiquitin ligase ligand; each R ⁴ and R ⁵ is independently H or C _1-6 alkyl; each R ⁶ and R ⁷ is independently H, C _1-6 alkyl, C _3-7 cycloalkyl, or 3- to 10-membered heterocycloalkyl; or R ⁶ and R ⁷ together with the nitrogen atom to which they are attached form a 3- to 8-membered heterocycloalkyl ring; and R ⁸ is independently H, C _1-6 alkyl, or 4- to 6-membered heterocycloalkyl; and wherein the compound comprises one and only one L ^P -E moiety. [0010] In embodiments, a compound of Formula (AI) has a structure selected from the group consisting of: or a pharmaceutically acceptable salt thereof, wherein R ² is H, unsubstituted C _1-6 alkyl or C _1-6 alkyl substituted by a group that is unsubstituted C _3-6 cycloalkyl; each X ⁸ , X ⁹ , and X ¹⁰ , when present, is CH or N. [0011] In embodiments, L ¹ -L ² -X ⁵ when present is CH(CH ₃ )-(CH ₂ ) ₂ -O, CH(CH ₃ )-(CH ₂ ) ₃ -O, CH(CH ₂ CH ₃ )-(CH ₂ ) ₂ -O, C(CH ₃ ) ₂ -(CH ₂ ) ₂ -O, (CH ₂ ) ₃ -O, CH ₂ -CH(CH ₃ )CH ₂ -O, CH ₂ - CH ₂ CH(CH ₃ )-O, CH(CH ₃ )-(CH ₂ ) ₂ -NH, CH(CH ₃ )-(CH ₂ ) ₂ -NCH ₃ , CH(CH ₃ )-(CH ₂ ) ₃ - NH, CH(CH ₃ )-(CH ₂ ) ₃ -NCH ₃ , CH(CH ₃ )-(CH ₂ ) ₃ , or CH(CH ₃ )-(CH ₂ ) ₄ , or L ¹ -L ² -X ⁵ is [0012] In embodiments, R ² is H or unsubstituted C _1-6 alkyl; or R ² is unsubstituted C _1-6 alkyl or C _1-6 alkyl substituted by a group that is unsubstituted C _3-6 cycloalkyl. [0013] In embodiments, a compound is selected from the group consisting of the compounds of Table A2, or a pharmaceutically acceptable salt thereof. [0014] In one aspect, the invention features a compound having a structure according to Formula (BI): or a pharmaceutically acceptable salt thereof, wherein A ¹ is independently phenylene or 5- or 6-membered heteroarylene; A ² is independently phenyl, naphthyl, or a 5- to 13-membered heteroaryl; X ¹ is independently O or X ^1A ; X ^1A is a covalent bond, S, NR ⁴ , C _1-6 alkylene, C _2-6 alkenylene, or C _2-6 alkynylene; each of X ² and X ³ is independently N or CR ^1B ; L ¹ is independently a covalent bond or C _1-6 alkylene; L ² is independently a covalent bond, C _2-6 alkenylene, C _2-6 alkynylene, C _3-6 cycloalkylene, 3- to 10-membered heterocyclylene, phenylene, or 5- or 6-membered heteroarylene; each R ^1A and R ^1B is independently H, OH, CN, halogen, C _1-6 aliphatic, C _1-6 alkoxy, NR ⁶ R ⁷ , C(O)R ⁸ , CO ₂ R ⁸ , C(O)NR ⁶ R ⁷ , NR ⁹ C(O)R ⁸ , NR ⁹ CO ₂ R ⁸ , NR ⁹ C(O)NR ⁶ R ⁷ , or R ¹⁰ ; each R ² , when present, is independently OH, CN, halogen, C _1-6 aliphatic, C _1-6 alkoxy, NR ⁶ R ⁷ , C(O)R ⁸ , CO ₂ R ⁸ , C(O)NR ⁶ R ⁷ , NR ⁹ C(O)R ⁸ , NR ⁹ CO ₂ R ⁸ , NR ⁹ C(O)NR ⁶ R ⁷ , R ¹⁰ , OR ¹⁰ , CH ₂ R ¹⁰ , CH ₂ CH ₂ R ¹⁰ , OCH ₂ R ¹⁰ , or OCH ₂ CH ₂ R ¹⁰ ; each R ³ , when present, is independently –L ^P -E, OH, CN, halogen, C _1-6 aliphatic, C _1-6 alkoxy, NR ⁶ R ⁷ , C(O)R ⁸ , CO ₂ R ⁸ , C(O)NR ⁶ R ⁷ , NR ⁹ C(O)R ⁸ , NR ⁹ CO ₂ R ⁸ , NR ⁹ C(O)NR ⁶ R ⁷ , R ¹⁰ , OR ¹⁰ , CH ₂ R ¹⁰ , CH ₂ CH ₂ R ¹⁰ , OCH ₂ R ¹⁰ , or OCH ₂ CH ₂ R ¹⁰ , and where valency permits when R ³ is not –L ^P -E, R ³ optionally further comprises –L ^P -E; L ^P is a linker; E is an E3 ubiquitin ligase ligand; each R ⁴ is independently H, a N-protecting group, or C _1-6 alkyl; R ⁵ is hydrogen; each R ⁶ , R ⁷ , and R ⁹ is independently H or C _1-6 alkyl; or R ⁶ and R ⁷ , together with the nitrogen atom to which they are attached, form a 3- to 10-membered heterocyclyl, or R ⁶ and R ⁹ , together with the atoms to which they are attached, form a 3- to 10-membered heterocyclyl; R ⁸ is independently C _1-6 aliphatic, C ₃ -C ₁₀ cycloaliphatic, 3- to 10-membered heterocyclyl, phenyl, naphthyl, or a 5- to 12-membered heteroaryl, or R ⁸ and R ⁹ , together with the atoms to which they are attached, form a 3- to 10-membered heterocyclyl; R ¹⁰ is independently C ₃ -C ₁₀ cycloaliphatic, 3- to 10-membered heterocyclyl, phenyl, naphthyl, or a 5- to 12-membered heteroaryl; each of n and o is independently 0, 1, or 2; wherein X ¹ is O, and both of X ² and X ³ are not N, then A ² is naphthyl or a bicyclic 8- to 12-membered heteroaryl; and wherein the compound comprises one and only one L ^P -E moiety. [0015] In embodiments, a compound of Formula (BI) has a structure selected from the group consisting of: or a pharmaceutically acceptable salt thereof. [0016] In embodiments, (a) the compound is according to Formula (BIX), (BX), or (BXI), or a pharmaceutically acceptable salt thereof, wherein L ¹ is C ₁ -C ₆ alkylene optionally substituted by 1, 2, or 3 R ¹³ ; each R ¹³ is independently unsubstituted C ₁ -C ₃ alkyl; and R ^1A is independently unsubstitued C ₁ -C ₆ alkyl or C ₁ -C ₆ haloalkyl; (b) the compound is according to Formula (BXII), or a pharmaceutically acceptable salt thereof, wherein R ^1A is independently unsubstitued C ₁ -C ₆ alkyl or C ₁ -C ₆ haloalkyl; or (c) the compound is according to Formula (BXIII) or (BXIV), or a pharmaceutically acceptable salt thereof, wherein L ¹ is C ₁ -C ₆ alkylene optionally substituted by 1 or 2 R ¹³ ; each R ¹³ is independently unsubstituted C ₁ -C ₃ alkyl; and R ^1A is independently unsubstitued C ₁ -C ₆ alkyl or C ₁ -C ₆ haloalkyl. [0017] In embodiments, a compound is selected from the group consisting of the compounds of Table B2, or a pharmaceutically acceptable salt thereof. [0018] In one aspect, the invention features a compound having a structure according to Formula (CI): or a pharmaceutically acceptable salt thereof, wherein X ² is independently N or CR ⁵ ; each of X ³ and X ⁴ is independently a covalent bond, O, S, NR ⁶ , C(O)NR ⁶ , NR ⁶ C(O), NR ⁶ C(O)NR ⁶ , or (C(R ⁷ ) ₂ ) _q ; L ¹ is independently a covalent bond, C _1-6 heteroalkylene, C _1-6 alkylene, C _2-6 alkenylene, C _2-6 alkynylene, C _3-6 cycloalkylene, 3- to 10-membered heterocyclylene, phenylene, or 5- to 10-membered heteroarylene; each R ¹ is independently L ^P -E, (Substructure A), OH, CN, halogen, C _1-6 aliphatic, C _1-6 alkoxy, NR ⁸ R ⁹ , C(O)R ¹⁰ , CO ₂ R ¹⁰ , C(O)NR ⁸ R ⁹ , NR ¹¹ C(O)R ¹⁰ , NR ¹¹ CO ₂ R ¹⁰ , NR ¹¹ C(O)NR ⁸ R ⁹ , or (CH ₂ )rR ¹² , or two R ¹ or two R ² , together to which the atoms they are attached form a 5- to 10-membered ring, and where valency permits when R ¹ is not –L ^P -E, R ¹ optionally further comprises –L ^P -E; each R ² is independently L ^P -E, (Substructure A), OH, CN, halogen, C _1-6 aliphatic, C _1-6 alkoxy, NR ⁸ R ⁹ , C(O)R ¹⁰ , CO ₂ R ¹⁰ , C(O)NR ⁸ R ⁹ , NR ¹¹ C(O)R ¹⁰ , NR ¹¹ CO ₂ R ¹⁰ , NR ¹¹ C(O)NR ⁸ R ⁹ , or (CH ₂ )rR ¹² , or two R ¹ or two R ² , together to which the atoms they are attached form a 5- to 10-membered ring, and where valency permits when R ² is not –L ^P -E, R ² optionally further comprises –L ^P -E; L ^P is a linker; E is an E3 ubiquitin ligase ligand; L ² is independently a covalent bond, O, NR ^L , C(O), C(O)NR ^L , NR ^L C(O), CR ^L ₂ ; R ^L is independently H or C _1-6 alkyl; A is independently phenyl, naphthyl, 5- to 13-membered heteroaryl, C ₃ -C ₁₀ cycloaliphatic, or 3- to 10-membered heterocyclyl; B is independently phenyl, naphthyl, 5- to 13-membered heteroaryl, C ₃ -C ₁₀ cycloaliphatic, or 3- to 10-membered heterocyclyl; C is independently 5- or 6-membered heteroaryl; each R ³ is independently OH, CN, halogen, C _1-6 aliphatic, C _1-6 alkoxy, NR ⁸ R ⁹ , C(O)R ¹⁰ , CO ₂ R ¹⁰ , C(O)NR ⁸ R ⁹ , NR ¹¹ C(O)R ¹⁰ , NR ¹¹ CO ₂ R ¹⁰ , NR ¹¹ C(O)NR ⁸ R ⁹ , or (CH ₂ )rR ¹² ; each R ⁴ is independently –L ^P -E, H, OH, CN, halogen, C _1-6 aliphatic, C _1-6 alkoxy, NR ⁸ R ⁹ , C(O)R ¹⁰ , CO ₂ R ¹⁰ , C(O)NR ⁸ R ⁹ , NR ¹¹ C(O)R ¹⁰ , NR ¹¹ CO ₂ R ¹⁰ , NR ¹¹ C(O)NR ⁸ R ⁹ , NR ¹¹ (CH ₂ ) _s NR ⁸ R ⁹ , (CH ₂ ) _t NR ⁸ R ⁹ , (CH ₂ ) _t OH, (CH ₂ ) _t OCH ₃ , O(CH ₂ ) _t OH, O(CH ₂ ) _t OCH ₃ , O(CH ₂ ) _r R ¹² , or (CH ₂ ) _r R ¹² ; or R ⁴ and R ⁶ or R ⁴ and R ⁷ , together with the atoms to which they are attached, form a 5- to 6-membered ring, and where valency permits when R ⁴ is not –L ^P -E, R ⁴ optionally further comprises –L ^P -E; each R ⁵ is independently H, OH, CN, halogen, C _1-6 aliphatic, C _1-6 alkoxy, NR ⁸ R ⁹ , C(O)R ¹⁰ , CO ₂ R ¹⁰ , C(O)NR ⁸ R ⁹ , NR ¹¹ C(O)R ¹⁰ , NR ¹¹ CO ₂ R ¹⁰ , NR ¹¹ C(O)NR ⁸ R ⁹ , or (CH ₂ ) _r R ¹² ; each R ⁶ is independently H, a N-protecting group, or C _1-6 alkyl; or R ⁶ and R ⁴ , together with the atoms to which they are attached, form a 5- to 6-membered ring; each R ⁷ is independently H or C _1-6 alkyl; or two R ⁷ on the same carbon combine to from an oxo (=O) group; or R ⁷ and R ⁴ , together with the atoms to which they are attached, form a 5- to 6-membered ring; each R ⁸ , R ⁹ , and R ¹¹ is independently H or C _1-6 alkyl; or R ⁸ and R ⁹ , together with the nitrogen atom to which they are attached, form a 3- to 10-membered heterocyclyl, or R ⁸ and R ¹¹ , together with the atoms to which they are attached, form a 3- to 10-membered heterocyclyl; each R ¹⁰ is independently C _1-6 aliphatic, C ₃ -C ₁₀ cycloaliphatic, 3- to 10-membered heterocyclyl, phenyl, naphthyl, or a 5- to 12-membered heteroaryl, or R ¹⁰ and R ¹¹ , together with the atoms to which they are attached, form a 3- to 10-membered heterocyclyl; each R ¹² is independently C ₃ -C ₁₀ cycloaliphatic, 3- to 10-membered heterocyclyl, phenyl, naphthyl, or a 5- to 12-membered heteroaryl; each m, n, and o, is independently 0, 1, or 2; each p is independently 0, 1, 2; 3, or 4; each q is independently 1 or 2; each r is independently an integer of 0-4; each s is independently an integer of 2-6; each t is independently an integer of 1-6; and wherein the compound comprises one and only one L ^P -E moiety. [0019] In embodiments, a compound of Formula (CI) has a structure selected from the group consisting of:

or a pharmaceutically acceptable salt thereof, wherein R ^4A is a first R ⁴ group, R ^4B is a second R ⁴ group, R ^4C is a third R ⁴ group, R ^4D is a fourth R ⁴ group, preferably R ⁴ is unsubstituted C _1-6 alkyl if one or more of R ^4A , R ^4B , and R ^4C is also present; and p is 0 or 1. [0020] In embodiments, a compound is selected from the group consisting of the compounds of Table C2 and Table C3, or a pharmaceutically acceptable salt thereof.

[0021] In embodiments, E is selected from the group consisting of:

15 [0022] In embodiments, a linker L ^P is a covalent bond. [0023] In embodiments, a linker L ^P comprises a C ₁ -C ₂₀ alkylene, a C ₂ -C ₂₀ heteroalkylene, a C ₂ -C ₂₀ monoalkynylene, and/or one or more ethyleneglycol moieties. [0024] In embodiments, a linker L ^P comprises one or more oxo (=O) substituents as valency permits. [0025] In embodiments, a linker L ^P comprises a heterocyclyl moiety that is attached to the EGFR ligand moiety of the compound via a covalent bond or via a CH ₂ or C(O) linker. [0026] In embodiments, a linker L ^P comprises a substructure F1 or a substructure F2 , wherein * denotes the point of attachment to the EGFR ligand moiety of the compound. [0027] In embodiments, a linker L ^P does not comprise a heterocyclyl moiety that is attached to the EGFR ligand moiety of the compound via a covalent bond or via a CH ₂ or C(O) linker. [0028] In embodiments, –L ^P -E comprises a structure or is a structure selected from the group consisting of:

[0029] In embodiments, –L ^P -E is a structure selected from the group consisting of:

[0030] In another aspect, the invention features a pharmaceutical composition comprising any compound described herein, or a pharmaceutically acceptable salt thereof.

[0031] In another aspect, the invention features a method of treating cancer comprising administering to a human in need thereof an effective amount of any compound described herein, or a pharmaceutically acceptable salt thereof, in a pharmaceutical composition.

[0032] In embodiments, a cancer is a lung cancer.

[0033] In embodiments, a cancer is non-small cell lung cancer.

[0034] In embodiments, a cancer (e.g., a lung cancer such as non-small cell lung cancer) is an EGFR-driven cancer.

[0035] In embodiments, a cancer (e.g., a lung cancer such as non-small cell lung cancer) is characterized by an EGFR mutation.

DETAILED DESCRIPTION OF THE INVENTION

Definitions

[0036] In order for the present invention to be more readily understood, certain terms are first defined below. Additional definitions for the following terms and other terms are set forth throughout the specification. The publications and other reference materials referenced herein to describe the background of the invention and to provide additional detail regarding its practice are hereby incorporated by reference. [0037] Animal: As used herein, the term “animal” refers to any member of the animal kingdom. In some embodiments, “animal” refers to humans, at any stage of development. In some embodiments, “animal” refers to non-human animals, at any stage of development. In certain embodiments, the non-human animal is a mammal (e.g., a rodent, a mouse, a rat, a rabbit, a monkey, a dog, a cat, a sheep, a bovine, a primate, and/or a pig). In some embodiments, animals include, but are not limited to, mammals, birds, reptiles, amphibians, fish, insects, and/or worms. In some embodiments, an animal may be a transgenic animal, genetically-engineered animal, and/or a clone. [0038] Approximately or about: As used herein, the term “approximately” or “about,” as applied to one or more values of interest, refers to a value that is similar to a stated reference value. In certain embodiments, the term “approximately” or “about” refers to a range of values that fall within 25%, 20%, 19%, 18%, 17%, 16%, 15%, 14%, 13%, 12%, 11%, 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%, or less in either direction (greater than or less than) of the stated reference value unless otherwise stated or otherwise evident from the context (except where such number would exceed 100% of a possible value). [0039] As used in the description and the appended claims, the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a composition” includes mixtures of two or more such compositions. [0040] Throughout the description and claims of this specification the word “comprise” and other forms of the word, such as “comprising” and “comprises,” means including but not limited to, and is not intended to exclude, for example, other additives, components, integers, or steps. [0041] “Optional” or “optionally” means that the subsequently described event or circumstance may or may not occur, and that the description includes instances where the event or circumstance occurs and instances where it does not. [0042] Improve, increase, or reduce: As used herein, the terms “improve,” “increase,” or “reduce,” or grammatical equivalents, indicate values that are relative to a baseline measurement, such as a measurement in the same individual prior to initiation of the treatment described herein, or a measurement in a control subject (or multiple control subject) in the absence of the treatment described herein. A “control subject” is a subject afflicted with the same form of disease as the subject being treated, who is about the same age as the subject being treated. [0043] In Vitro: As used herein, the term “in vitro” refers to events that occur in an artificial environment, e.g., in a test tube or reaction vessel, in cell culture, etc., rather than within a multi-cellular organism. [0044] In Vivo: As used herein, the term “in vivo” refers to events that occur within a multi- cellular organism, such as a human and a non-human animal. In the context of cell-based systems, the term may be used to refer to events that occur within a living cell (as opposed to, for example, in vitro systems). [0045] Patient: As used herein, the term “patient” or “subject” refers to any organism to which a provided composition may be administered, e.g., for experimental, diagnostic, prophylactic, cosmetic, and/or therapeutic purposes. Typical patients include animals (e.g., mammals such as mice, rats, rabbits, non-human primates, and/or humans). In some embodiments, a patient is a human. A human includes pre- and post-natal forms. [0046] Pharmaceutically acceptable: The term “pharmaceutically acceptable,” as used herein, refers to substances that, within the scope of sound medical judgment, are suitable for use in contact with the tissues of human beings and animals without excessive toxicity, irritation, allergic response, or other problem or complication, commensurate with a reasonable benefit/risk ratio. Accordingly, pharmaceutically acceptable relates to substances that are not biologically or otherwise undesirable, i.e., the material can be administered to an individual along with the relevant active compound without causing clinically unacceptable biological effects or interacting in a deleterious manner with any of the other components of the pharmaceutical composition in which it is contained. [0047] Pharmaceutically acceptable salt: Pharmaceutically acceptable salts are well known in the art. For example, S. M. Berge et al., describes pharmaceutically acceptable salts in detail in J. Pharmaceutical Sciences (1977) 66:1–19. Pharmaceutically acceptable salts of the compounds of this invention include those derived from suitable inorganic and organic acids and bases. Examples of pharmaceutically acceptable, nontoxic acid addition salts are salts of an amino group formed with inorganic acids such as hydrochloric acid, hydrobromic acid, phosphoric acid, sulfuric acid, and perchloric acid or with organic acids such as acetic acid, oxalic acid, maleic acid, tartaric acid, citric acid, succinic acid, or malonic acid, or by using other methods used in the art such as ion exchange. Other pharmaceutically acceptable salts include adipate, alginate, ascorbate, aspartate, benzenesulfonate, benzoate, bisulfate, borate, butyrate, camphorate, camphorsulfonate, citrate, cyclopentanepropionate, digluconate, dodecylsulfate, ethanesulfonate, formate, fumarate, glucoheptonate, glycerophosphate, gluconate, hemisulfate, heptanoate, hexanoate, hydroiodide, 2-hydroxy-ethanesulfonate, lactobionate, lactate, laurate, lauryl sulfate, malate, maleate, malonate, methanesulfonate, 2- naphthalenesulfonate, nicotinate, nitrate, oleate, oxalate, palmitate, pamoate, pectinate, persulfate, 3-phenylpropionate, phosphate, picrate, pivalate, propionate, stearate, succinate, sulfate, tartrate, thiocyanate, p-toluenesulfonate, undecanoate, valerate salts, and the like. Salts derived from appropriate bases include alkali metal, alkaline earth metal, ammonium and N ⁺ (C _1–4 -alkyl) ₄ salts. Representative alkali or alkaline earth metal salts include sodium, lithium, potassium, calcium, magnesium, and the like. Further pharmaceutically acceptable salts include, when appropriate, nontoxic ammonium. quaternary ammonium, and amine cations formed using counterions such as halide, hydroxide, carboxylate, sulfate, phosphate, nitrate, sulfonate, and aryl sulfonate. Further pharmaceutically acceptable salts include salts formed from the quarternization of an amine using an appropriate electrophile, e.g., an alkyl halide, to form a quarternized alkylated amino salt. [0048] Subject: As used herein, the term “subject” refers to a human or any non-human animal (e.g., mouse, rat, rabbit, dog, cat, cattle, swine, sheep, horse or primate). A human includes pre- and post-natal forms. In many embodiments, a subject is a human being. A subject can be a patient, which refers to a human presenting to a medical provider for diagnosis or treatment of a disease. The term “subject” is used herein interchangeably with “individual” or “patient.” A subject can be afflicted with or is susceptible to a disease or disorder but may or may not display symptoms of the disease or disorder. [0049] Substantially: As used herein, the term “substantially” refers to the qualitative condition of exhibiting total or near-total extent or degree of a characteristic or property of interest. One of ordinary skill in the biological arts will understand that biological and chemical phenomena rarely, if ever, go to completion and/or proceed to completeness or achieve or avoid an absolute result. The term “substantially” is therefore used herein to capture the potential lack of completeness inherent in many biological and chemical phenomena. [0050] Therapeutically effective amount: As used herein, the term “therapeutically effective amount” of a therapeutic agent means an amount that is sufficient, when administered to a subject suffering from or susceptible to a disease, disorder, and/or condition, to treat, diagnose, prevent, and/or delay the onset of the symptom(s) of the disease, disorder, and/or condition. It will be appreciated by those of ordinary skill in the art that a therapeutically effective amount is typically administered via a dosing regimen comprising at least one unit dose. [0051] Treating: As used herein, the term “treat,” “treatment,” or “treating” refers to any method used to partially or completely alleviate, ameliorate, relieve, inhibit, prevent, delay onset of, reduce severity of and/or reduce incidence of one or more symptoms or features of a particular disease, disorder, and/or condition. Treatment may be administered to a subject who does not exhibit signs of a disease and/or exhibits only early signs of the disease for the purpose of decreasing the risk of developing pathology associated with the disease. [0052] Whenever a term (e.g., alkyl or aryl) or either of their prefix roots (e.g., alk- or ar-) appear in a name of a substituent the name is to be interpreted as including those limitations provided herein. For example, affixing the suffix “-ene” to a group indicates the group is a divalent moiety, e.g., arylene is the divalent moiety of aryl, heteroarylene is the divalent moiety of heteroaryl, and heterocycloalkylene is the divalent moiety of heterocycloalkyl. Similarly, affixing the suffix “-oxy” to a group indicates the group is attached to the parent molecular structure through an oxygen atom (-O-). [0053] Alkyl: As used herein, the term “alkyl” means acyclic linear and branched hydrocarbon groups, e.g. “C ₁ -C ₂₀ alkyl” refers to alkyl groups having 1–20 carbons and “ C ₁ –C ₄ alkyl” refers to alkyl groups having 1–4 carbons. Alkyl groups include C ₁ -C ₂₀ alkyl, C ₁ -C ₁₅ alkyl, C ₁ –C ₁₀ alkyl, C ₁ –C ₄ alkyl, and C ₁ –C ₃ alkyl). In embodiments, an alkyl group is C ₁ –C ₄ alkyl. An alkyl group may be linear or branched. Examples of alkyl groups include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, isopentyl tert-pentylhexyl, isohexyl, etc. The term “lower alkyl" means an alkyl group straight chain or branched alkyl having 1 to 6 carbon atoms. Other alkyl groups will be readily apparent to those of skill in the art given the benefit of the present disclosure. An alkyl group may be unsubstituted or substituted with one or more substituent groups as described herein. For example, an alkyl group may be substituted with one or more (e.g., 1, 2, 3, 4, 5, or 6 independently selected substituents) of halogen, -COR’, -CO ₂ H, -CO ₂ R’, -CN, -OH, -OR’, - OCOR’, -OCO ₂ R’, -NH ₂ , -NHR’, -N(R’) ₂ , -SR’ or-SO ₂ R’, wherein each instance of R’ independently is C ₁ -C ₂₀ aliphatic (e.g., C ₁ -C ₂₀ alkyl, C ₁ -C ₁₅ alkyl, C ₁ –C ₁₀ alkyl, C ₁ –C ₄ alkyl, or C ₁ –C ₃ alkyl). In some embodiments, R’ independently is an unsubstituted alkyl (e.g., unsubstituted C ₁ -C ₂₀ alkyl, C ₁ -C ₁₅ alkyl, C ₁ –C ₁₀ alkyl, or C ₁ –C ₃ alkyl). In some embodiments, R’ independently is unsubstituted C ₁ –C ₃ alkyl. In some embodiments, the alkyl is substituted (e.g., with 1, 2, 3, 4, 5, or 6 substituent groups as described herein). In some embodiments, an alkyl group is substituted with a–OH group and may also be referred to herein as a “hydroxyalkyl” group, where the prefix denotes the –OH group and “alkyl” is as described herein. In some embodiments, an alkyl group is substituted with a–OR’ group. [0054] Alkylene: The term “alkylene,” as used herein, represents a saturated divalent straight or branched chain hydrocarbon group and is exemplified by methylene, ethylene, isopropylene and the like. Likewise, the term “alkenylene” as used herein represents an unsaturated divalent straight or branched chain hydrocarbon group having one or more unsaturated carbon-carbon double bonds that may occur in any stable point along the chain, and the term “alkynylene” herein represents an unsaturated divalent straight or branched chain hydrocarbon group having one or more unsaturated carbon-carbon triple bonds that may occur in any stable point along the chain. In certain embodiments, an alkylene, alkenylene, or alkynylene group may comprise one or more cyclic aliphatic and/or one or more heteroatoms such as oxygen, nitrogen, or sulfur and may optionally be substituted with one or more substituents such as alkyl, halo, alkoxyl, hydroxy, amino, aryl, ether, ester or amide. For example, an alkylene, alkenylene, or alkynylene may be substituted with one or more (e.g., 1, 2, 3, 4, 5, or 6 independently selected substituents) of halogen, -COR’, -CO ₂ H, -CO ₂ R’, -CN, -OH, -OR’, -OCOR’, -OCO ₂ R’, -NH ₂ , -NHR’, -N(R’) ₂ , -SR’ or -SO ₂ R’, wherein each instance of R’ independently is C ₁ –C ₂₀ aliphatic (e.g., C ₁ -C ₂₀ alkyl, C ₁ -C ₁₅ alkyl, C ₁ –C ₁₀ alkyl, or C ₁ –C ₃ alkyl). In some embodiments, R’ independently is an unsubstituted alkyl (e.g., unsubstituted C ₁ -C ₂₀ alkyl, C ₁ – C ₁₅ alkyl, C ₁ –C ₁₀ alkyl, or C ₁ –C ₃ alkyl). In some embodiments, R’ independently is unsubstituted C ₁ –C ₃ alkyl. In certain embodiments, an alkylene, alkenylene, or alkynylene is unsubstituted. In certain embodiments, an alkylene, alkenylene, or alkynylene does not include any heteroatoms. [0055] Alkenyl: As used herein, “alkenyl” means any linear or branched hydrocarbon chains having one or more unsaturated carbon-carbon double bonds that may occur in any stable point along the chain, e.g. “C ₂ -C ₂₀ alkenyl” refers to an alkenyl group having 2–20 carbons. For example, an alkenyl group includes prop-2-enyl, but-2-enyl, but-3-enyl, 2-methylprop-2- enyl, hex-2-enyl, hex-5-enyl, 2,3-dimethylbut-2-enyl, and the like. In some embodiments, the alkenyl comprises 1, 2, or 3 carbon-carbon double bond. In some embodiments, the alkenyl comprises a single carbon-carbon double bond. In some embodiments, multiple double bonds (e.g., 2 or 3) are conjugated. An alkenyl group may be unsubstituted or substituted with one or more substituent groups as described herein. For example, an alkenyl group may be substituted with one or more (e.g., 1, 2, 3, 4, 5, or 6 independently selected substituents) of halogen, -COR’, -CO ₂ H, -CO ₂ R’, -CN, -OH, -OR’, -OCOR’, -OCO ₂ R’, -NH ₂ , -NHR’, - N(R’) ₂ , -SR’ or-SO ₂ R’, wherein each instance of R’ independently is C ₁ –C ₂₀ aliphatic (e.g., C ₁ -C ₂₀ alkyl, C ₁ -C ₁₅ alkyl, C ₁ –C ₁₀ alkyl, or C ₁ –C ₃ alkyl). In some embodiments, R’ independently is an unsubstituted alkyl (e.g., unsubstituted C ₁ -C ₂₀ alkyl, C ₁ -C ₁₅ alkyl, C ₁ –C ₁₀ alkyl, or C ₁ –C ₃ alkyl). In some embodiments, R’ independently is unsubstituted C ₁ -C ₃ alkyl. In some embodiments, the alkenyl is unsubstituted. In some embodiments, the alkenyl is substituted (e.g., with 1, 2, 3, 4, 5, or 6 substituent groups as described herein). In some embodiments, an alkenyl group is substituted with a–OH group and may also be referred to herein as a “hydroxyalkenyl” group, where the prefix denotes the –OH group and “alkenyl” is as described herein. [0056] Alkynyl: As used herein, “alkynyl” means any hydrocarbon chain of either linear or branched configuration, having one or more carbon-carbon triple bonds occurring in any stable point along the chain, e.g. “C ₂ -C ₂₀ alkynyl” refers to an alkynyl group having 2–20 carbons. Examples of an alkynyl group include prop-2-ynyl, but-2-ynyl, but-3-ynyl, pent-2- ynyl, 3-methylpent-4-ynyl, hex-2-ynyl, hex-5-ynyl, etc. In some embodiments, an alkynyl comprises one carbon-carbon triple bond. An alkynyl group may be unsubstituted or substituted with one or more substituent groups as described herein. For example, an alkynyl group may be substituted with one or more (e.g., 1, 2, 3, 4, 5, or 6 independently selected substituents) of halogen, -COR’, -CO ₂ H, -CO ₂ R’, -CN, -OH, -OR’, -OCOR’, -OCO ₂ R’, -NH ₂ , -NHR’, -N(R’) ₂ , -SR’ or-SO ₂ R’, wherein each instance of R’ independently is C ₁ -C ₂₀ aliphatic (e.g., C ₁ -C ₂₀ alkyl, C ₁ -C ₁₅ alkyl, C ₁ –C ₁₀ alkyl, or C ₁ –C ₃ alkyl). In some embodiments, R’ independently is an unsubstituted alkyl (e.g., unsubstituted C ₁ -C ₂₀ alkyl, C ₁ – C ₁₅ alkyl, C ₁ –C ₁₀ alkyl, or C ₁ –C ₃ alkyl). In some embodiments, R’ independently is unsubstituted C ₁ –C ₃ alkyl. In some embodiments, the alkynyl is unsubstituted. In some embodiments, the alkynyl is substituted (e.g., with 1, 2, 3, 4, 5, or 6 substituent groups as described herein). [0057] Alkoxy: The term “alkoxy” refers to the group -O-alkyl, including from 1 to 10 carbon atoms of a straight, branched, saturated cyclic configuration and combinations thereof, attached to the parent molecular structure through an oxygen. Examples include methoxy, ethoxy, propoxy, isopropoxy, butoxy, t-butoxy, pentoxy, cyclopropyloxy, cyclohexyloxy and the like. “Lower alkoxy” refers to alkoxy groups containing one to six carbons. In some embodiments, C _1-4 alkoxy is an alkoxy group which encompasses both straight and branched chain alkyls of from 1 to 4 carbon atoms. Unless stated otherwise in the specification, an alkoxy group can be optionally substituted by one or more substituents (e.g., as described herein for alkyl). The terms “alkenoxy” and “alkynoxy” mirror the above description of “alkoxy” wherein the prefix “alk” is replaced with “alken” or “alkyn” respectively, and the parent “alkenyl" or “alkynyl” terms are as described herein. [0058] Amide: The term “amide” or “amido” refers to a chemical moiety with formula -C(O)N(R’) ₂ , -C(O)N(R’)-, -NR’C(O)R’, or -NR’C(O)-, where each R’ is independently selected from hydrogen, alkyl, alkenyl, alkynyl, heteroalkyl (bonded through a chain carbon), cycloalkyl, aryl, arylalkyl, heteroaryl (bonded through a ring carbon), heteroarylalkyl, or heterocycloalkyl (bonded through a ring carbon), unless stated other-wise in the specification, each of which moiety can itself be optionally substituted as described herein, or two R’ can combine with the nitrogen atom to form a 3-, 4-, 5-, 6-, or 7-membered ring. [0059] Amino: The term “amino” or “amine” refers to a -N(R’) ₂ group, where each R’ is independently selected from hydrogen, alkyl, alkenyl, alkynyl, heteroalkyl (bonded through a chain carbon), cycloalkyl, aryl, arylalkyl, heteroaryl (bonded through a ring carbon), heteroarylalkyl, or heterocycloalkyl (bonded through a ring carbon), unless stated otherwise in the specification, each of which moiety can itself be optionally substituted as described herein, or two R’ can combine with the nitrogen atom to form a 3-, 4-, 5-, 6-, or 7-membered ring. In embodiments, an amino group is –NHR’, where R’ is aryl (“arylamino”), heteroaryl (“heteroarylamino”), or alkyl (“alkylamino”). [0060] Aryl: The term “aryl” used alone or as part of a larger moiety as in “aralkyl,” refers to a monocyclic, bicyclic, or tricyclic carbocyclic ring system having a total of six to fourteen ring members, wherein said ring system has a single point of attachment to the rest of the molecule, wherein at least one ring in the system is aromatic, and wherein each ring in the system contains 4 to 7 ring members. In some embodiments, an aryl group has 6 ring carbon atoms (“C ₆ aryl,” e.g., phenyl). In some embodiments, an aryl group has 10 ring carbon atoms (“C ₁₀ aryl,” e.g., naphthyl such as 1-naphthyl and 2-naphthyl). In some embodiments, an aryl group has 14 ring carbon atoms (“C ₁₄ aryl,” e.g., anthracyl). “Aryl” also includes ring systems wherein the aryl ring, as defined above, is fused with one or more carbocyclyl or heterocyclyl groups wherein the radical or point of attachment is on the aryl ring, and in such instances, the number of carbon atoms continue to designate the number of carbon atoms in the aryl ring system. Exemplary aryls include phenyl, naphthyl, and anthracene. [0061] Arylalkyl: The term “arylalkyl” refers to an –(alkylene)-aryl radical where aryl and alkylene are as disclosed herein and which are optionally substituted by one or more of the exemplary substituent groups described herein. The “arylalkyl” group is bonded to the parent molecular structure through the alkylene moiety. The term “arylalkoxy” refers to an -O- [arylalkyl] radical (-O-[(alkylene)-aryl]), which is attached to the parent molecular structure through the oxygen. [0062] Arylene: The term “arylene” as used herein refers to an aryl group that is divalent (that is, having two points of attachment to the molecule). Exemplary arylenes include phenylene (e.g., unsubstituted phenylene or substituted phenylene). [0063] Cyclic: The term “cyclic” as used herein, refers to any covalently closed structure. Cyclic moieties include, for example, carbocycles (e.g., aryls and cycloalkyls), heterocycles (e.g., heteroaryls and heterocycloalkyls), aromatics (e.g. aryls and heteroaryls), and non- aromatics (e.g., cycloalkyls and heterocycloalkyls). In some embodiments, cyclic moieties are optionally substituted. In some embodiments, cyclic moieties form part of a ring system. [0064] Cycloaliphatic: The term “cycloaliphatic” refers to a monocyclic or polycyclic radical that contains only carbon and hydrogen, and can be saturated or partially unsaturated. Fully saturated cycloaliphatics can be termed “cycloalkyl”. Partially unsaturated cycloalkyl groups can be termed “cycloalkenyl” if the carbocycle contains at least one double bond, or "cycloalkynyl" if the carbocycle contains at least one triple bond. Cycloaliphatic groups include groups having from 3 to 13 ring atoms (e.g., C _3–13 cycloalkyl). Whenever it appears herein, a numerical range such as “3 to 10” refers to each integer in the given range; e.g., “3 to 10 carbon atoms” means that the cycloaliphatic group (e.g., cycloalkyl) can consist of 3 carbon atoms, 4 carbon atoms, 5 carbon atoms, etc., up to and including 10 carbon atoms. The term “cycloaliphatic” also includes bridged and spiro-fused cyclic structures containing no heteroatoms. The term also includes monocyclic or fused-ring polycyclic (i.e., rings which share adjacent pairs of ring atoms) groups. Polycyclic cycloaliphatic groups include bicycles, tricycles, tetracycles, and the like. In some embodiments, “cycloalkyl” can be a C _3-8 cycloalkyl group. In some embodiments, “cycloalkyl” can be a C _3-5 cycloalkyl group. Illustrative examples of cycloaliphatic groups include, but are not limited to the following moieties: C _3–6 cycloaliphatic groups include, without limitation, cyclopropyl (C ₃ ), cyclobutyl (C ₄ ), cyclopentyl (C ₅ ), cyclopentenyl (C ₅ ), cyclohexyl (C ₆ ), cyclohexenyl (C ₆ ), cyclohexadienyl (C ₆ ) and the like. Examples of C _3–7 cycloaliphatic groups include norbornyl (C ₇ ). Examples of C _3-8 cycloaliphatic groups include the aforementioned C3–7 carbocyclyl groups as well as cycloheptyl(C ₇ ), cycloheptadienyl (C ₇ ), cyclohept-atrienyl (C ₇ ), cyclooctyl (C ₈ ), bicyclo[2.2.1]heptanyl, bicyclo[2.2.2]octanyl, and the like. Examples of C _3-13 cycloaliphatic groups include the aforementioned C _3-8 carbocyclyl groups as well as octahydro-1H indenyl, decahydronaphthalenyl, spiro[4.5]decanyl, and the like. [0065] Cyano: The term “cyano” refers to a –CN group. [0066] Deuterium: The term “deuterium” is also called heavy hydrogen. Deuterium is isotope of hydrogen with a nucleus consisting of one proton and one neutron, which is double the mass of the nucleus of ordinary hydrogen (one proton). In embodiments, deuterium can also be identified as ² H. [0067] Ester: The term “ester” refers to a group of formula –C(O)OR’ or –R’OC(O)-, where R’ is selected from alkyl, alkenyl, alkynyl, heteroalkyl (bonded through a chain carbon), cycloalkyl, aryl, arylalkyl, heteroaryl, heteroarylalkyl, or heterocycloalkyl as described herein. [0068] Halogen or Halo: As used herein, the term “halogen” or “halo” means fluorine, chlorine, bromine, or iodine. [0069] Heteroalkyl: The term “heteroalkyl” is meant a branched or unbranched alkyl, alkenyl, or alkynyl group having from 1 to 14 carbon atoms in addition to 1, 2, 3 or 4 heteroatoms independently selected from the group consisting of N, O, S, and P. Heteroalkyls include tertiary amines, secondary amines, ethers, thioethers, amides, thioamides, carbamates, thiocarbamates, hydrazones, imines, phosphodiesters, phosphoramidates, sulfonamides, and disulfides. A heteroalkyl group may optionally include monocyclic, bicyclic, or tricyclic rings, in which each ring desirably has three to six members. Examples of heteroalkyls include polyethers, such as methoxymethyl and ethoxyethyl. Accordingly, the term “heteroalkoxy” refers to the group -O-heteroalkyl, where the group is attached to the parent molecular structure via the oxygen. [0070] Heteroalkylene: The term “heteroalkylene,” as used herein, represents a divalent form of a heteroalkyl group as described herein. [0071] Heteroaryl: The term “heteroaryl,” as used herein, refers to a monocyclic, bicyclic, or tricyclic carbocyclic ring system having a total of six to fourteen ring members, wherein said ring system has a single point of attachment to the rest of the molecule, wherein at least one ring in the system is aromatic, wherein each ring in the system contains 4 to 7 ring members, and wherein at least one ring atom is a heteroatom such as, but not limited to, nitrogen and oxygen. Examples of heteroaryl groups are pyridinyl, imidazolyl, pyrimidinyl, pyrazolyl, triazolyl, pyrazinyl, tetrazolyl, furyl, thienyl, isoxazolyl, thiazolyl, oxazolyl, isothiazolyl, pyrrolyl, quinolinyl, isoquinolinyl, indolyl, benzimidazolyl, benzofuranyl, cinnolinyl, indazolyl, indolizinyl, phthalazinyl, pyridazinyl, triazinyl, isoindolyl, pteridinyl, purinyl, oxadiazolyl, thiadiazolyl, furazanyl, benzofurazanyl, benzothiophenyl, benzothiazolyl, benzoxazolyl, quinazolinyl, quinoxalinyl, naphthyridinyl, and furopyridinyl. Accordingly, the term “heteroaryloxy” refers to the group -O-heteroaryl, where the group is attached to the parent molecular structure via the oxygen. [0072] Heteroarylalkyl: The term “heteroarylalkyl” refers to an –(alkylene)-heteroaryl radical where heteroaryl and alkylene are as disclosed herein and which are optionally substituted by one or more of the exemplary substituent groups described herein. The “heteroarylalkyl” group is bonded to the parent molecular structure through the alkylene moiety. The term “heteroarylalkoxy” refers to an -O-[heteroarylalkyl] radical (-O-[(alkylene)-heteroaryl]), which is attached to the parent molecular structure through the oxygen. [0073] Heterocycloalkyl: The term “heterocycloalkyl” as used herein, is a non-aromatic ring wherein at least one atom is a heteroatom such as, but not limited to, nitrogen, oxygen, sulfur, or phosphorus, and the remaining atoms are carbon. Examples of heterocycloalkyl groups are pyrrolidinyl, tetrahydrofuranyl, dihydrofuranyl, tetrahydrothienyl, tetrahydropyranyl, dihydropyranyl, tetrahydrothiopyranyl, piperidino, morpholino, thiomorpholino, thioxanyl, piperazinyl, azetidinyl, oxetanyl, thietanyl, homopiperidinyl, oxepanyl, thiepanyl, oxazepinyl, diazepinyl, thiazepinyl, 1,2,3,6-tetrahydropyridinyl, 2-pyrrolinyl, 3-pyrrolinyl, indolinyl, 2H- pyranyl, 4H-pyranyl, dioxanyl, 1,3-dioxolanyl, pyrazolinyl, dithianyl, dithiolanyl, dihydropyranyl, dihydrothienyl, dihydrofuranyl, pyrazolidinyl, imidazolinyl, imidazolidinyl, 3-azabicyclo[3.1.0]hexanyl, 3-azabicyclo[4.1.0]heptanyl, 3H-indolyl and quinolizinyl. The heterocycloalkyl group can be substituted or unsubstituted. [0074] Heterocycle: The term “heterocycle” or “heterocyclyl” refers to groups containing one to four heteroatoms each selected from O, S and N, wherein each heterocycle group has from 4 to 10 atoms in its ring system, and with the proviso that the ring of said group does not contain two adjacent O or S atoms. Herein, whenever the number of carbon atoms in a heterocycle is indicated (e.g., C ₁ –C ₆ -heterocycle), at least one other atom (the heteroatom) must be present in the ring. Designations such as “C ₁ –C ₆ -heterocycle” refer only to the number of carbon atoms in the ring and do not refer to the total number of atoms in the ring. In some embodiments, it is understood that the heterocycle ring has additional heteroatoms in the ring. Designations such as “4–6-membered heterocycle” refer to the total number of atoms that are contained in the ring (i.e., a four, five, or six membered ring, in which at least one atom is a carbon atom, at least one atom is a heteroatom and the remaining two to four atoms are either carbon atoms or heteroatoms). In some embodiments, in heterocycles that have two or more heteroatoms, those two or more heteroatoms are the same or different from one another. In some embodiments, heterocycles are optionally substituted. In some embodiments, binding to a heterocycle is at a heteroatom or via a carbon atom. Heterocycloalkyl groups include groups having only 4 atoms in their ring system, but heteroaryl groups must have at least 5 atoms in their ring system. The heterocycle groups include benzo-fused ring systems. An example of a 4-membered heterocycle group is azetidinyl (derived from azetidine). An example of a 5-membered heterocycle group is thiazolyl. An example of a 6-membered heterocycle group is pyridyl, and an example of a 10-membered heterocycle group is quinolinyl. In some embodiments, the foregoing groups, as derived from the groups listed above, are C-attached or N-attached where such is possible. For instance, in some embodiments, a group derived from pyrrole is pyrrol-1-yl (N-attached) or pyrrol-3-yl (C- attached). Further, in some embodiments, a group derived from imidazole is imidazol-1-yl or imidazol-3-yl (both N-attached) or imidazol-2-yl, imidazol-4-yl or imidazol-5-yl (all C- attached). The heterocycle groups include benzo-fused ring systems and ring systems substituted with one or two oxo (=O) moieties such as pyrrolidin-2-one. In some embodiments, depending on the structure, a heterocycle group is a monoradical or a diradical (i.e., a heterocyclene group). The heterocycles described herein are substituted with 0, 1, 2, 3, or 4 substituents independently selected from alkenyl, alkoxy, alkoxyalkyl, alkoxycarbonyl, alkyl, alkylcarbonyl, alkylcarbonyloxy, alkylthio, alkylthioalkyl, alynyl, carboxy, cyano, formyl, haloalkoxy, haloalkyl, halogen, hydroxyl, hydroxyalkylene, mercapto, nitro, amino, and amido moities. [0075] Isotope: The term “isotope” refers to a variant of a particular chemical element which differs in neutron number, and consequently in nucleon number. All isotopes of a given element have the same number of protons but different numbers of neutrons in each atom. [0076] Nitro: The term “nitro” refers to a –NO ₂ group. [0077] Sulfonamide: The term “sulfonamide” or sulfonamido” refers to the following groups: -S(=O) ₂ -(R’) ₂ , -N(R’)-S(=O) ₂ -R’, -S(=O) ₂ -N(R’)-, or -N(R’)-S(=O) ₂ -,where each R ^’ is independently selected from hydrogen, alkyl, alkenyl, alkynyl, heteroalkyl (bonded through a chain carbon), cycloalkyl, aryl, arylalkyl, heteroaryl (bonded through a ring carbon), heteroarylalkyl, or heterocycloalkyl (bonded through a ring carbon), unless stated other-wise in the specification, each of which moiety can itself be optionally substituted as described herein, or two R’ can combine with the nitrogen atom to form a 3-, 4-, 5-, 6-, or 7-membered ring. [0078] Moiety: The term “moiety” refers to a specific segment or functional group of a molecule. Chemical moieties are often recognized chemical entities embedded in or appended to a molecule. [0079] Molecular groups herein may be substituted or unsubstituted (e.g., as described herein). The term “substituted” means that the specified group or moiety bears one or more substituents: at least one hydrogen present on a group atom (e.g., a carbon or nitrogen atom) is replaced with a permissible substituent, e.g., a substituent which upon substitution for the hydrogen results in a stable compound, e.g., a compound which does not spontaneously undergo transformation such as by rearrangement, cyclization, elimination, or other reaction. The term “unsubstituted” means that the specified group bears no substituents. The term “optionally substituted” means that the specified group is unsubstituted or substituted by one or more substituents. Where the term “substituted” is used to describe a structural system, the substitution is meant to occur at any valency-allowed position on the system. In embodiments, a group described herein is substituted. In embodiments, a group described herein is unsubstituted. In cases where a specified moiety or group is not expressly noted as being optionally substituted or substituted with any specified substituent, it is understood that such a moiety or group is intended to be unsubstituted. [0080] A wide variety of substituents are well known, and methods for their formation and introduction into a variety of parent groups are also well known. Representative substituents include but are not limited to alkyl, cycloalkyl, alkenyl, cycloalkenyl, alkynyl, arylalkyl, alkylaryl, aryl, heteroaryl, heterocycloalkyl, hydroxyalkyl, arylalkyl, aminoalkyl, haloalkyl, thioalkyl, alkylthioalkyl, carboxyalkyl, imidazolylalkyl, indolylalkyl, mono-, di- and trihaloalkyl, mono-, di- and trihaloalkoxy, amino, alkylamino, dialkylamino, alkoxy, hydroxy, halo (e.g., —Cl and —Br), nitro, oximino, —COOR ⁵⁰ , —COR ⁵⁰ , —SO _0-2 R ⁵⁰ , —SO ₂ NR ⁵⁰ R ⁵¹ , —NR ⁵² SO ₂ R ⁵⁰ , ═C(R ⁵⁰ R ⁵¹ ), ═N—OR ⁵⁰ , ═N—CN, ═C(halo) ₂ , ═S, ═O, —CON(R ⁵⁰ R ⁵¹ ), — OCOR ⁵⁰ , —OCON(R ⁵⁰ R ⁵¹ ), —N(R ⁵² )CO(R ⁵⁰ ), —N(R ⁵² )COOR ⁵⁰ , —N(R ⁵² )CON(R ⁵⁰ (R ⁵¹ ), — P(OR ⁵⁰ ) ₂ , —P(O)R ⁵⁰ R ⁵¹ , and —P(O)OR ⁵⁰ OR ⁵¹ , wherein R ⁵⁰ , R ⁵¹ and R ⁵² may be independently selected from the following: a hydrogen atom and a branched or straight-chain, C1–6-alkyl, C3–6-cycloalkyl, C4–6-heterocycloalkyl, heteroaryl and aryl group, with or without substituents. When permissible, R ⁵⁰ and R ⁵¹ can be joined together to form a carbocyclic or heterocyclic ring system. [0081] In preferred embodiments, the substituent is selected from halogen, -COR’, -CO ₂ H, - CO ₂ R’, -CN, -OH, -OR’, -OCOR’, -OCO ₂ R’, -NH ₂ , -NHR’, -N(R’) ₂ , -SR’, and -SO ₂ R’, wherein each instance of R’ independently is C ₁ -C ₂₀ aliphatic (e.g., C ₁ -C ₂₀ alkyl, C ₁ -C ₁₅ alkyl, C ₁ –C ₁₀ alkyl, or C ₁ –C ₃ alkyl). In certain embodiments thereof, R’ independently is an unsubstituted alkyl (e.g., unsubstituted C ₁ –C ₂₀ alkyl, C ₁ –C ₁₅ alkyl, C ₁ –C ₁₀ alkyl, or C ₁ –C ₃ alkyl). Preferably, R’ independently is unsubstituted C ₁ –C ₃ alkyl. [0082] Any formula given herein is intended to represent compounds having structures depicted by the structural formula as well as certain variations or forms. In particular, compounds of any formula given herein may have asymmetric centers and therefore exist in different enantiomeric forms. All optical isomers and stereoisomers of the compounds of the general formula, and mixtures thereof, are considered within the scope of the formula. Thus, any formula given herein is intended to represent a racemate, one or more enantiomeric forms, one or more diastereomeric forms, one or more atropisomeric forms, and mixtures thereof. Furthermore, certain structures may exist as geometric isomers (i.e., cis and trans isomers), as tautomers, or as atropisomers. Additionally, any formula given herein is intended to embrace hydrates, solvates, and polymorphs of such compounds, and mixtures thereof. EGFR Inhibitors [0083] Compounds of the invention can be be effective as as proteolysis-targetic chimera (PROTAC) therapies, including for the treatment of cancers characterized by mutant EGFR, including EGFR comprising one or more resistance mutations. [0084] Accordingly, EGFR PROTAC compounds described herein comprise the following structural features: (1) a ligand targeting EGFR; (2) a linker L ^P , wherein the linker is covalently attached to the ligand and an E3 ubiquitin ligase ligand; and (3) a moiety E, which is an E3 ubiquitin ligase ligand. [0085] Exemplary formulas, compounds, and structural features are described herein. [0086] Any structural feature described herein (e.g., for any exemplary formula described herein) can be used in combination with any other structural feature(s) described for any exemplary formula described herein. In particular, any exemplary permitted feature for ligands, linkers L ^P , and moieties E (E3 ubiquitin ligase ligand) can be used in any combination to arrive at suitable compounds. Exemplary ligands [0087] Exemplary EGFR ligands that can be incorporated into the compounds described herein include any of the EGFR inhibitor formulas and compounds described in any of the below disclosures, each of which is incorporated in its reference in its entirety: • International Patent Publication No. WO2021/168074 (“Class A ligands”); • International Patent Application No. PCT/US22/21999 (“Class B ligands”); and • International Patent Application No. PCT/US22/28755 (“Class C ligands”). [0088] In embodiments, a compound of the invention as described herein comprises or is derived from a Class A ligand, including any formulae or specific compound as described in WO2021/168074, including any compound according to any one of Formulas (I), (I’), (I-A), (I-B), (I-C), (I-D), (I-E), (I-F), (I-G), (I-H), and (I-J), such as any one of Compounds (1)-(58), (61)-(71), (73)-(80), and (82)-(193), or a pharmaceutically acceptable salt thereof. [0089] In embodiments, a compound of the invention as described herein comprises or is derived from a Class B ligand, including any formulae or specific compound as described in PCT/US22/21999, including any compound according to any one of Formulas (I), (II), (III), (IV), (V), (VI), (VII), (VIII), (IX), (X), (XI), (XII), (XIII), and (XIV) such as any one of Compounds (1)-(71), or a pharmaceutically acceptable salt thereof. [0090] In embodiments, a compound of the invention as described herein comprises or is derived from a Class C ligand, including any formulae or specific compound as described in PCT/US22/28755, including any compound according to Formula (I), (II), (III), (IV), (V), (VI), (VII), (VIII), (IX), (X), (XI), (XII), (XIII), (XIV), (XV), (XVI), (XVII), (XVIII), (XIX), (XX), (XXI), (XXII), and (XXIII), such as any one of Compounds (1)-(169), or a pharmaceutically acceptable salt thereof. [0091] In embodiments, a derivative of a formula or compound described in any of WO2021/168074, PCT/US22/21999, and PCT/US22/28755 includes modification of a formula or compound to include a functional group for covalent attachment to the L ^P -E moiety (e.g., as described herein). An exemplary derivative includes modification of any formula or compound described in WO2021/168074, PCT/US22/21999, and PCT/US22/28755 to comprise a piperazine or piperazine-containing group that is covalently attached to an L ^P -E moiety. Exemplary Compounds Comprising a Class A Ligand [0092] In embodiments, the invention features compounds comprising a Class A ligand or comprising a moiety derived from a Class A ligand. [0093] In embodiments, a compound of the invention as described herein comprises or is derived from a Class A ligand, wherein said ligand is according to or derived from any one of Formulas (I), (I’), (I-A), (I-B), (I-C), (I-D), (I-E), (I-F), (I-G), (I-H), and (I-J) of WO2021/168074, such as any one of Compounds (1)-(58), (61)-(71), (73)-(80), and (82)- (193), or a pharmaceutically acceptable salt thereof. [0094] Certain exemplary structure features are described herein. Exemplary structural formulae and compounds can feature any combination of features as described herein. [0095] In embodiments of compounds comprising or derived from a Class A Ligand, E and L ^P are according to any embodiments described herein, as well as any combinations thereof. [0096] In one embodiment, the invention features a compound having a structure according to Formula (AI), or a pharmaceutically acceptable salt thereof, wherein: A is C _6-10 arylene, 5-12-membered heteroarylene, or 5-12-membered heterocycloalkylene; X ¹ is N or CR ^X ; X ² is N or CR ^X ; X ³ is N or CR ^X” ; X ⁴ is N or CR ^X” ; X ⁶ is N or CR ^X’ ; X ⁷ is N or CR ^X’ ; ------ represents an optional double bond between X ⁷ and X ⁴ or X ⁴ and X ⁶ , wherein one and only one double bond is present; X ⁵ is a covalent bond, CH ₂ , O, NR ⁴ , C(O)NR ⁴ , or NR ⁴ C(O); L ¹ is a covalent bond or C(R ⁵ ) ₂ , and L ² is C _1-4 alkylene, or L ¹ and L ² combine to form a C _3-6 cycloalkyl or a 4- to 6-membered heterocycloalkyl; R ¹ is –L ^P -E, halogen, C _1-6 alkyl, C _3-7 cycloalkyl, C _6-10 aryl, 5- to 10-membered heteroaryl, 3- to 10-membered heterocycloalkyl, CN, NR ⁶ R ⁷ , NR ⁶ C(O)R ⁷ , NR ⁶ C(O)NH ₂ , OR ⁸ , or C(O)NR ⁶ R ⁷ , and where valency permits when R ¹ is not –L ^P -E, R ¹ optionally further comprises -L ^P -E; R ² is absent, H, C _1-6 alkyl, halogen, CN, or C _1-6 alkoxy; each R ³ , when present, is independently OH, CN, halogen, C _1-6 alkyl, or C _1-6 alkoxy; n is 0, 1, or 2; each R ^X is independently H, OR ^X1 , CN, halogen, or C _1-6 alkyl, wherein R ^X1 is H or C _{1- 6} alkyl; each R ^X’ is independently H, OR ^X1 , CN, halogen, or C _1-6 alkyl, wherein R ^X1 is H or C _{1- 6} alkyl, or R ^X’ is absent if the carbon to which it is attached is part of a double bond; each R ^X” is independently –L ^P -E, H, OR ^X1 , CN, halogen, or C _1-6 alkyl optionally comprising -L ^P -E, and wherein R ^X1 is H or C _1-6 alkyl optionally comprising –L ^P -E; L ^P is a linker; E is an E3 ubiquitin ligase ligand; each R ⁴ and R ⁵ is independently H or C _1-6 alkyl; each R ⁶ and R ⁷ is independently H, C _1-6 alkyl, C _3-7 cycloalkyl, or 3- to 10-membered heterocycloalkyl; or R ⁶ and R ⁷ together with the nitrogen atom to which they are attached form a 3- to 8-membered heterocycloalkyl ring; and R ⁸ is independently H, C _1-6 alkyl, or 4- to 6-membered heterocycloalkyl; and wherein the compound comprises one and only one L ^P -E moiety. [0097] Certain exemplary structure features are described herein. Exemplary structural formulae and compounds can feature any combination of features as described herein. [0098] In embodiments, ------ represents a double bond between X ⁷ and X ⁴ , and there is a single bond between X ⁶ and X ⁴ . In embodiments, X ⁷ is N and X ⁴ is CR ^X . In embodiments, X ⁷ is C and X ⁴ is CR ^X . In embodiments, X ⁷ is N and X ⁴ is N. In embodiments, X ⁶ is N. In embodiments, X ⁶ is CR ^X (e.g., C-H). [0099] In embodiments, ------ represents a double bond between X ⁶ and X ⁴ , and there is a single bond between X ⁷ and X ⁴ . In embodiments, X ⁶ is C, and X ⁴ is CR ^X . In embodiments, X ⁶ is C, and X ⁴ is N. In embodiments, X ⁷ is N. In embodiments, X ⁷ is CR ^X (e.g., C-H). [0100] In embodiments, A is C _6-10 arylene. In embodiments, A is unsubstituted C _6-10 arylene. In embodiments, A is substituted C _6-10 arylene (e.g., comprising 1, 2, 3, or 4 substituents as described herein). [0101] In embodiments, A is 5-12-membered heteroarylene. In embodiments, A is unsubstituted 5-12-membered heteroarylene. In embodiments, A is substituted 5-12-membered heteroarylene (e.g., comprising 1, 2, 3, or 4 substituents as described herein). [0102] In embodiments, A is 5-12-membered heterocycloalkylene. In embodiments, A is unsubstituted 5-12-membered heterocycloalkylene. In embodiments, A is substituted 5-12- membered heterocycloalkylene (e.g., comprising 1, 2, 3, or 4 substituents as described herein). [0103] In embodiments, X ¹ is N. In embodiments, X ¹ is CR ^X (e.g., C-H or C-CH ₃ ). [0104] In embodiments, X ² is N. In embodiments, X ² is CR ^X (e.g., C-H or C-CH ₃ ). [0105] In embodiments, X ³ is N. In embodiments, X ³ is CR ^X” (e.g., C-H or C-CH ₃ ). [0106] In embodiments, X ⁴ is N. In embodiments, X ⁴ is CR ^X” (e.g., C-H or C-CH ₃ ). [0107] In embodiments, X ⁶ is N. In embodiments, X ⁶ is CR ^X’ (e.g., C, C-H, or C-CH ₃ ). [0108] In embodiments, X ⁷ is N. In embodiments, X ⁷ is CR ^X’ (e.g., C, C-H, or C-CH ₃ ). [0109] In embodiments, X ⁵ is a covalent bond. In embodiments, X ⁵ is CH ₂ . In embodiments, X ⁵ is O. In embodiments, X ⁵ is NR ⁴ (e.g., NH or NCH ₃ ). In embodiments, X ⁵ is C(O)NR ⁴ (e.g., C(O)NH or C(O)CH ₃ ). In embodiments, X ⁵ is NR ⁴ C(O) (e.g., NHC(O) or NCH ₃ C(O)). [0110] In embodiments, L ¹ is a covalent bond or C(R ⁵ ) ₂ , and L ² is C _1-4 alkylene. In embodiments, L ¹ is a covalent bond. In embodiments, L ¹ is C(R ⁵ ) ₂ (e.g., CH ₂ , CHCH ₃ , CH(CH ₂ CH ₃ ), or C(CH ₃ ) ₂ ). In embodiments, L ² is unsubstituted C _1-4 alkylene (e.g. CH ₂ , (CH ₂ ) ₂ , (CH ₂ ) ₃ , or (CH ₂ ) ₄ ). In embodiments, L ² is substituted C _1-4 alkylene (e.g., C _1-4 alkylene substituted by OH, oxo (=O), or unsubstituted C _1-3 alkyl)). [0111] In embodiments, L ¹ and L ² combine to form a C _3-6 cycloalkyl or a 4- to 6-membered heterocycloalkyl. In embodiments, L ¹ and L ² combine to form a C _3-6 cycloalkyl. In embodiments, L ¹ and L ² combine to form cyclopropyl. In embodiments, L ¹ and L ² combine to form cyclobutyl. In embodiments, L ¹ and L ² combine to form cyclopentyl. In embodiments, L ¹ and L ² combine to form cyclohexyl. In embodiments, L ¹ and L ² combine to form an unsubstituted C _4-6 cycloalkyl. In embodiments, L ¹ and L ² combine to form a substituted C _4-6 cycloalkyl (e.g., comprising 1, 2, or 3 substituents as described herein). In embodiments, L ¹ and L ² combine to form a 4- to 6-membered heterocycloalkyl. In embodiments, L ¹ and L ² combine to form tetrahydropyranyl. In embodiments, L ¹ and L ² combine to form an unsubstituted 4- to 6-membered heterocycloalkyl. In embodiments, L ¹ and L ² combine to form a substituted 4- to 6-membered heterocycloalkyl (e.g., comprising 1, 2, or 3 substituents as described herein). [0112] In embodiments, R ¹ is halogen. In embodiments, R ¹ is C _1-6 alkyl. In embodiments, R ¹ is C _3-7 cycloalkyl. In embodiments, R ¹ is C _6-10 aryl. In embodiments, R ¹ is 5- to 10-membered heteroaryl (e.g., monocyclic or bicyclic heteroaryl). In embodiments, R ¹ is 3- to 10-membered heterocycloalkyl (e.g., monocyclic or bicyclic heterocycloalkyl). In embodiments, R ¹ is CN. In embodiments, R ¹ is NR ⁶ R ⁷ . In embodiments, R ¹ is NR ⁶ C(O)R ⁷ . In embodiments, R ¹ is NR ⁶ C(O)NH ₂ . In embodiments, R ¹ is OR ⁸ . In embodiments, R ¹ is C(O)NR ⁶ R ⁷ . [0113] In embodiments, R ¹ is unsubstituted C _1-6 alkyl. In embodiments, R ¹ is unsubstituted C _3-7 cycloalkyl. In embodiments, R ¹ is unsubstituted C _6-10 aryl. In embodiments, R ¹ is unsubstituted 5- to 10-membered heteroaryl (e.g., unsubstituted monocyclic or bicyclic heteroaryl). In embodiments, R ¹ is unsubstituted 3- to 10-membered heterocycloalkyl (e.g., unsubstituted monocyclic or bicyclic heterocycloalkyl). In embodiments, R ¹ is –L ^P -E. In embodiments, when R ¹ is not –L ^P -E, R ¹ optionally further comprises -L ^P -E. In embodiments, R ¹ further comprises -L ^P -E. [0114] In embodiments, R ¹ is substituted C _1-6 alkyl. In embodiments, R ¹ is substituted C _3-7 cycloalkyl. In embodiments, R ¹ is substituted C _6-10 aryl. In embodiments, R ¹ is substituted 5- to 10-membered heteroaryl (e.g., substituted monocyclic or bicyclic heteroaryl). In embodiments, R ¹ is substituted 3- to 10-membered heterocycloalkyl (e.g., substituted monocyclic or bicyclic heterocycloalkyl). In embodiments, a substituted group comprises 1, 2, or 3 substituent groups as described herein. [0115] In embodiments, R ¹ is a substituted or unsubstituted 5- or 6-membered heteroarylene; a substituted or unsubstituted 5- or 6-membered heterocycloalkyl, C _1-6 alkyl substituted by a 5- or 6-membered heteroarylene that is substituted or unsubstituted; or C _1-6 alkyl substituted by a 5- or 6-membered heterocycloalkyl that is substituted or unsubstituted, or substituted phenyl. [0116] In embodiments, R ² is absent. In embodiments, R ² is H. In embodiments, R ² is C _1-6 alkyl. In embodiments, R ² is halogen. In embodiments, R ² is CN. In embodiments, R ² is C _1-6 alkoxy. In embodiments, R ² is unsubstituted C _1-6 alkyl. In embodiments, R ² is substituted C _1-6 alkyl (e.g., comprising 1, 2, or 3 substituent groups as described herein). In embodiments, R ² is unsubstituted C _1-6 alkoxy. In embodiments, R ² is substituted C _1-6 alkoxy (e.g., comprising 1, 2, or 3 substituent groups as described herein). [0117] In embodiments, R ³ is not present. In embodiments, R ³ is present. In embodiments, R ³ is OH. In embodiments, R ³ is CN. In embodiments, R ³ is halogen. In embodiments, R ³ is C _1-6 alkyl. In embodiments, R ³ is C _1-6 alkoxy. In embodiments, R ³ is unsubstituted C _1-6 alkyl. In embodiments, R ³ is substituted C _1-6 alkyl (e.g., comprising 1, 2, or 3 substituent groups as described herein). In embodiments, R ³ is unsubstituted C _1-6 alkoxy. In embodiments, R ³ is substituted C _1-6 alkoxy (e.g., comprising 1, 2, or 3 substituent groups as described herein). [0118] In embodiments, n is 0. In embodiments, n is 1. In embodiments, n is 2. [0119] In embodiments, R ^X is H. In embodiments, R ^X is OR ^X1 . In embodiments, R ^X is CN. In embodiments, R ^X is halogen. In embodiments, R ^X is C _1-6 alkyl. In embodiments, R ^X is unsubstituted C _1-6 alkyl. In embodiments, R ^X is substituted C _1-6 alkyl (e.g., comprising 1, 2, or 3 substituent groups as described herein). [0120] In embodiments, R ^X’ is H. In embodiments, R ^X’ is OR ^X1 . In embodiments, R ^X’ is CN. In embodiments, R ^X’ is halogen. In embodiments, R ^X’ is C _1-6 alkyl. In embodiments, R ^X’ is absent if the carbon to which it is attached is part of a double bond. [0121] In embodiments, R ^X” is H. In embodiments, R ^X” is OR ^X1 . In embodiments, R ^X” is CN. In embodiments, R ^X” is halogen. In embodiments, R ^X” is C _1-6 alkyl. In embodiments, R ^X” is absent if the carbon to which it is attached is part of a double bond. In embodiments, R ^X” is – L ^P -E. In embodiments, when R ^X” is not –L ^P -E, R ¹ optionally further comprises -L ^P -E. In embodiments, R ^X” further comprises -L ^P -E. [0122] In embodiments, R ^X1 is H. In embodiments, R ^X1 is C _1-6 alkyl. In embodiments, R ^X1 is unsubstituted C _1-6 alkyl. In embodiments, R ^X1 is substituted C _1-6 alkyl (e.g., comprising 1, 2, or 3 substituent groups as described herein). [0123] In embodiments, R ⁴ is H. embodiments, R ⁴ is C _1-6 alkyl. In embodiments, R ⁴ is unsubstituted C _1-6 alkyl. In embodiments, R ⁴ is substituted C _1-6 alkyl (e.g., comprising 1, 2, or 3 substituent groups as described herein). [0124] In embodiments, R ⁵ is H. embodiments, R ⁵ is C _1-6 alkyl. In embodiments, R ⁵ is unsubstituted C _1-6 alkyl. In embodiments, R ⁵ is substituted C _1-6 alkyl (e.g., comprising 1, 2, or 3 substituent groups as described herein). [0125] In embodiments, R ⁶ is H. In embodiments, R ⁶ is C _1-6 alkyl. In embodiments, R ⁶ is C _3-7 cycloalkyl. In embodiments, R ⁶ is 3- to 10-membered heterocycloalkyl (e.g. monocyclic or bicyclic heterocycloalkyl). In embodiments, R ⁶ is unsubstituted C _1-6 alkyl. In embodiments, R ⁶ is unsubstituted C _3-7 cycloalkyl. In embodiments, R ⁶ is unsubstituted 3- to 10-membered heterocycloalkyl (e.g. monocyclic or bicyclic heterocycloalkyl). In embodiments, R ⁶ is substituted C _1-6 alkyl (e.g., comprising 1, 2, or 3 substituent groups as described herein). In embodiments, R ⁶ is substituted C _3-7 cycloalkyl (e.g., comprising 1, 2, or 3 substituent groups as described herein). In embodiments, R ⁶ is substituted 3- to 10-membered heterocycloalkyl (e.g. a monocyclic or bicyclic heterocycloalkyl comprising 1, 2, or 3 substituent groups as described herein). [0126] In embodiments, R ⁷ is H. In embodiments, R ⁷ is C _1-6 alkyl. In embodiments, R ⁷ is C _3-7 cycloalkyl. In embodiments, R ⁷ is 3- to 10-membered heterocycloalkyl (e.g. monocyclic or bicyclic heterocycloalkyl). In embodiments, R ⁷ is unsubstituted C _1-6 alkyl. In embodiments, R ⁷ is unsubstituted C _3-7 cycloalkyl. In embodiments, R ⁷ is unsubstituted 3- to 10-membered heterocycloalkyl (e.g. monocyclic or bicyclic heterocycloalkyl). In embodiments, R ⁷ is substituted C _1-6 alkyl (e.g., comprising 1, 2, or 3 substituent groups as described herein). In embodiments, R ⁷ is substituted C _3-7 cycloalkyl (e.g., comprising 1, 2, or 3 substituent groups as described herein). In embodiments, R ⁷ is substituted 3- to 10-membered heterocycloalkyl (e.g. a monocyclic or bicyclic heterocycloalkyl comprising 1, 2, or 3 substituent groups as described herein). [0127] In embodiments, R ⁶ and R ⁷ together with the nitrogen atom to which they are attached form a 3- to 8-membered heterocycloalkyl ring (e.g., monocyclic or bicyclic heterocycloalkyl). [0128] In embodiments, R ⁸ is H. In embodiments, R ⁸ is C _1-6 alkyl. In embodiments, R ⁸ is 4- to 6-membered heterocycloalkyl. In embodiments, R ⁸ is unsubstituted C _1-6 alkyl. In embodiments, R ⁸ is substituted C _1-6 alkyl (e.g., comprising 1, 2, or 3 substituent groups as described herein). In embodiments, R ⁸ is a substituted C _1-6 alkyl that is piperidinyl substituted C _1-6 alkyl (e.g., -CH ₂ CH ₂ (piperidinyl)). In embodiments, R ⁸ is unsubstituted 4- to 6- membered heterocycloalkyl. In embodiments, R ⁸ is substituted 4- to 6-membered heterocycloalkyl (e.g., comprising 1, 2, or 3 substituent groups as described herein). [0129] In embodiments, a compound of the invention comprising a Class A ligand has a structure selected from the following formulas selected from Table A1. In embodiments, an E moiety is selected from those described in Table D, where shows the point of covalent attachment to moiety L ^P . In embodiments, -L ^P -E is according to any of substructures (D1)- (D49) as described herein. In embodiments, -L ^P -E is according to any of substructures (D1)’- (D49)’ as described herein. Table A1. Exemplary Formulas Comprising Class A Ligands or a pharmaceutically acceptable salt thereof. [0130] In embodiments, R ² is H, unsubstituted C _1-6 alkyl or C _1-6 alkyl substituted by a group that is unsubstituted C _3-6 cycloalkyl. [0131] In embodiments, each X ⁸ , X ⁹ , and X ¹⁰ , when present, is CH or N. [0132] In embodiments, L ¹ -L ² -X ⁵ when present is CH(CH ₃ )-(CH ₂ ) ₂ -O, CH(CH ₃ )-(CH ₂ ) ₃ -O, CH(CH ₂ CH ₃ )-(CH ₂ ) ₂ -O, C(CH ₃ ) ₂ -(CH ₂ ) ₂ -O, (CH ₂ ) ₃ -O, CH ₂ -CH(CH ₃ )CH ₂ -O, CH ₂ - CH ₂ CH(CH ₃ )-O, CH(CH ₃ )-(CH ₂ ) ₂ -NH, CH(CH ₃ )-(CH ₂ ) ₂ -NCH ₃ , CH(CH ₃ )-(CH ₂ ) ₃ - NH, CH(CH ₃ )-(CH ₂ ) ₃ -NCH ₃ , CH(CH ₃ )-(CH ₂ ) ₃ , or CH(CH ₃ )-(CH ₂ ) ₄ , or L ¹ -L ² -X ⁵ is [0133] In embodiments, R ² is H or unsubstituted C _1-6 alkyl. [0134] In embodiments, R ² is unsubstituted C _1-6 alkyl or C _1-6 alkyl substituted by a group that is unsubstituted C _3-6 cycloalkyl. [0135] In embodiments, the compound comprises a ligand formed from any one Compounds (1)-(58), (61)-(71), (73)-(80), and (82)-(193) of WO2021/168074, or a pharmaceutically acceptable salt thereof. [0136] In embodiments, the compound comprises a ligand derived from any one of Compounds (1)-(58), (61)-(71), (73)-(80), and (82)-(193) of WO2021/168074, or a pharmaceutically acceptable salt thereof. In embodiments, the compound of WO2021/168074 is modified to include a piperazine- or piperazine-containing group covalently attached to the -L ^P -E group as described herein. [0137] In embodiments, the compound is selected from any of the following compounds of Table A2, or a pharmaceutically acceptable salt thereof. In embodiments, an E moiety is selected from those described in Table D, where shows the point of covalent attachment to moiety L ^P . In embodiments, -L ^P -E is according to any of substructures (D1)-(D49) as described herein. Table A2. Exemplary Compounds Comprising Class A Ligands

Exemplary Compounds Comprising a Class B Ligand [0138] In embodiments, the invention features compounds comprising a Class B ligand. In embodiments, a compound of the invention as described herein comprises or is derived from a Class B ligand, wherein said ligand is according to or derived from any one of Formulas (I), (II), (III), (IV), (V), (VI), (VII), (VIII), (IX), (X), (XI), (XII), (XIII), and (XIV) of PCT/US22/21999 such as any one of Compounds (1)-(71), or a pharmaceutically acceptable salt thereof. [0139] Certain exemplary structure features are described herein. Exemplary structural formulae and compounds can feature any combination of features as described herein. [0140] In embodiments of compounds comprising or derived from a Class B Ligand, E and L ^P are according to any embodiments described herein, as well as any combinations thereof. [0141] In one embodiment, the invention features a compound having a structure according to Formula (BI), or a pharmaceutically acceptable salt thereof, wherein A ¹ is independently phenylene or 5- or 6-membered heteroarylene; A ² is independently phenyl, naphthyl, or a 5- to 13-membered heteroaryl; X ¹ is independently O or X ^1A ; X ^1A is a covalent bond, S, NR ⁴ , C _1-6 alkylene, C _2-6 alkenylene, or C _2-6 alkynylene; each of X ² and X ³ is independently N or CR ^1B ; L ¹ is independently a covalent bond or C _1-6 alkylene; L ² is independently a covalent bond, C _2-6 alkenylene, C _2-6 alkynylene, C _3-6 cycloalkylene, 3- to 10-membered heterocyclylene, phenylene, or 5- or 6-membered heteroarylene; each R ^1A and R ^1B is independently H, OH, CN, halogen, C _1-6 aliphatic, C _1-6 alkoxy, NR ⁶ R ⁷ , C(O)R ⁸ , CO ₂ R ⁸ , C(O)NR ⁶ R ⁷ , NR ⁹ C(O)R ⁸ , NR ⁹ CO ₂ R ⁸ , NR ⁹ C(O)NR ⁶ R ⁷ , or R ¹⁰ ; each R ² , when present, is independently OH, CN, halogen, C _1-6 aliphatic, C _1-6 alkoxy, NR ⁶ R ⁷ , C(O)R ⁸ , CO ₂ R ⁸ , C(O)NR ⁶ R ⁷ , NR ⁹ C(O)R ⁸ , NR ⁹ CO ₂ R ⁸ , NR ⁹ C(O)NR ⁶ R ⁷ , R ¹⁰ , OR ¹⁰ , CH ₂ R ¹⁰ , CH ₂ CH ₂ R ¹⁰ , OCH ₂ R ¹⁰ , or OCH ₂ CH ₂ R ¹⁰ ; each R ³ , when present, is independently –L ^P -E, OH, CN, halogen, C _1-6 aliphatic, C _1-6 alkoxy, NR ⁶ R ⁷ , C(O)R ⁸ , CO ₂ R ⁸ , C(O)NR ⁶ R ⁷ , NR ⁹ C(O)R ⁸ , NR ⁹ CO ₂ R ⁸ , NR ⁹ C(O)NR ⁶ R ⁷ , R ¹⁰ , OR ¹⁰ , CH ₂ R ¹⁰ , CH ₂ CH ₂ R ¹⁰ , OCH ₂ R ¹⁰ , or OCH ₂ CH ₂ R ¹⁰ , and where valency permits when R ³ is not –L ^P -E, R ³ optionally further comprises –L ^P -E; L ^P is a linker; E is an E3 ubiquitin ligase ligand; each R ⁴ is independently H, a N-protecting group, or C _1-6 alkyl; R ⁵ is hydrogen; each R ⁶ , R ⁷ , and R ⁹ is independently H or C _1-6 alkyl; or R ⁶ and R ⁷ , together with the nitrogen atom to which they are attached, form a 3- to 10-membered heterocyclyl, or R ⁶ and R ⁹ , together with the atoms to which they are attached, form a 3- to 10-membered heterocyclyl; R ⁸ is independently C _1-6 aliphatic, C ₃ -C ₁₀ cycloaliphatic, 3- to 10-membered heterocyclyl, phenyl, naphthyl, or a 5- to 12-membered heteroaryl, or R ⁸ and R ⁹ , together with the atoms to which they are attached, form a 3- to 10-membered heterocyclyl; R ¹⁰ is independently C ₃ -C ₁₀ cycloaliphatic, 3- to 10-membered heterocyclyl, phenyl, naphthyl, or a 5- to 12-membered heteroaryl; each of n and o is independently 0, 1, or 2; and wherein the compound comprises one and only one L ^P -E moiety. In embodiments, when X ¹ is O, and both of X ² and X ³ are not N, then A ² is naphthyl or a bicyclic 8- to 12-membered heteroaryl. In embodiments, X ² is N. In embodiments, X ² is CR ^1B (e.g., CH). In embodiments, X ³ is N. In embodiments, X ³ is CR ^1B (e.g., CH). In embodiments, each of X ² and X ³ is N. In embodiments, each of X ² and X ³ is CR ^1B . In embodiments, each of X ² and X ³ is CH. In embodiments, one of X ² and X ³ is N, and the other is CR ^1B (e.g., CH). In embodiments, at least one of X ² and X ³ is N. In embodiments, X ¹ is X ^1A . In embodiments, X ^1A is a covalent bond. In embodiments, X ^1A is S or NR ⁴ . In embodiments, X ^1A is C _1-6 alkylene, C _2-6 alkenylene, or C _2-6 alkynylene. In embodiments, L ¹ is a covalent bond. In embodiments, L ¹ is unsubstituted branched C _1-6 alkylene, or linear C _1-6 alkylene optionally comprising a -OH substituent. In embodiments, X ¹ is X ^1A , wherein X ^1A is a covalent bond, C _1-6 alkylene, C _2-6 alkenylene, or C _2-6 alkynylene; L ¹ is independently a covalent bond or C _1-6 alkylene; L ² is independently a covalent bond, C _2-6 alkenylene, C _2-6 alkynylene, C _3-6 cycloalkylene, 3- to 10-membered heterocyclylene, phenylene, or 5- or 6-membered heteroarylene; and where at least one of X ^1A , L ¹ , and L ² is a covalent bond. In embodiments, one X ^1A and L ¹ is a covalent bond and the other is C _1-6 alkylene; and L ² is a covalent bond. In embodiments, each of L ¹ and L ² is a covalent bond. In embodiments, each of X ^1A and L ² is a covalent bond. In embodiments, each of X ^1A and L ¹ is a covalent bond. In embodiments, X ² is N. In embodiments, X ² is CR ^1B (e.g., CH). In embodiments, X ³ is N. In embodiments, X ³ is CR ^1B (e.g., CH). In embodiments, each of X ² and X ³ is N. In embodiments, each of X ² and X ³ is CR ^1B . In embodiments, each of X ² and X ³ is CH. In embodiments, one of X ² and X ³ is N, and the other is CR ^1B (e.g., CH). In embodiments, at least one of X ² and X ³ is N. In embodiments, A ¹ is phenylene. In embodiments, A ¹ is unsubstituted phenylene. In embodiments, A ¹ is substituted phenylene (e.g., comprising 1 or 2 substituents as described herein). In embodiments, A ¹ is 5- or 6-membered heteroarylene. Examplary 5- to 6-membered heteroarylene includes but is not limited to pyridylene, pyrimidylene, pyrazolylene, thiazolylene, oxazolylene, and imidazolylene. In embodiments, A ¹ is unsubstituted 5- or 6- membered heteroarylene. In embodiments, A ¹ is substituted 5- or 6-membered heteroarylene (e.g., comprising 1 or 2 substituents as described herein). In embodiments, A ¹ is pyrazolylene. In embodiments, A ¹ is unsubstituted pyrazolylene. In embodiments, A ¹ is substituted pyrazolylene (e.g., comprising 1 or 2 substituents as described herein). In embodiments, A ¹ is N-substituted pyrazolylene (e.g., N-methyl pyrazolylene). In embodiments, A ² is phenyl. In embodiments, A ² is unsubstituted phenyl. In embodiments, A ² is substituted phenyl (e.g., comprising 1 or 2 substituents as described herein). In embodiments, A ² is naphthyl. In embodiments, A ² is unsubstituted naphthyl. In embodiments, A ² is substituted naphthyl (e.g., comprising 1 or 2 substituents as described herein). In embodiments, A ² is 5- to 13-membered heteroaryl (e.g., monocyclic or bicyclic heteroaryl). In embodiments, A ² is a monocyclic 5- to 6-membered heteroaryl. Examplary monocyclic 5- to 6-membered heteroaryls include but are not limited to pyridyl, pyrimidyl, pyrazolyl, thiazolyl, oxazolyl, and imidazolyl. In embodiments, A ² is a bicyclic 8- to 12-membered heteroaryl (e.g., nitrogen-containing, bicyclic 8- to 12-membered heteroaryl). Examplary bicyclic 8- to 12-membered heteroaryls include but are not limited to indolyl, benzimidazolyl, indazolyl, isoindolyl, pyrrolopyrimidyl, pyrrolopyridinyl, pyrazolopyrimidyl, pyrazolopyridinyl, benzotriazolyl, quinolyl, and isoquinolyl. In embodiments, A ² is pyrazolyl. In embodiments, A ² is unsubstituted 5- to 13-membered heteroaryl (e.g., unsubstituted monocyclic or bicyclic heteroaryl). In embodiments, A ² is unsubstituted monocyclic 5- to 6-membered heteroaryls. In embodiments, A ² is unsubstituted pyridyl, unsubstituted pyrimidyl, unsubstituted pyrazolyl, unsubstituted thiazolyl, unsubstituted oxazolyl, or unsubstituted imidazolyl. In embodiments, A ² is unsubstituted bicyclic 8- to 12-membered heteroaryl (e.g., unsubstituted nitrogen-containing, bicyclic 8- to 12-membered heteroaryl). In embodiments, A ² is unsubstituted indolyl, unsubstituted benzimidazolyl, unsubstituted indazolyl, unsubstituted isoindolyl, unsubstituted pyrrolopyrimidyl, unsubstituted pyrrolopyridinyl, unsubstituted pyrazolopyrimidyl, unsubstituted pyrazolopyridinyl, unsubstituted benzotriazolyl, unsubstituted quinolyl, or unsubstituted isoquinolyl. In embodiments, A ² is unsubstituted pyrazolyl. In embodiments, A ² is substituted 5- to 13-membered heteroaryl (e.g., substituted monocyclic or bicyclic heteroaryl comprising 1 or 2 substituents as described herein). In embodiments, A ² is substituted monocyclic 5- to 6-membered heteroaryls. In embodiments, A ² is substituted pyridyl, substituted pyrimidyl, substituted pyrazolyl, substituted thiazolyl, substituted oxazolyl, or substituted imidazolyl. In embodiments, A ² is substituted bicyclic 8- to 12- membered heteroaryl (e.g., substituted nitrogen-containing, bicyclic 8- to 12-membered heteroaryl). In embodiments, A ² is substituted indolyl, substituted benzimidazolyl, substituted indazolyl, substituted isoindolyl, substituted pyrrolopyrimidyl, substituted pyrrolopyridinyl, substituted pyrazolopyrimidyl, substituted pyrazolopyridinyl, substituted benzotriazolyl, substituted quinolyl, or substituted isoquinolyl. Examplary substituent groups include but are not limited to methyl, halogen (e.g. F, Cl, Br, or I), and CN. In embodiments, A ² is substituted pyrazolyl (e.g, N-substituted pyrazolyl such as N-methyl pyrazolyl). In embodiments, when X ¹ is O, and both of X ² and X ³ are not N, then A ² is naphthyl or a bicyclic 8- to 12-membered heteroaryl. In embodiments, X ¹ is not O. In embodiments, R ^1A is H. In embodiments, R ^1A is OH. In embodiments, R ^1A is CN. In embodiments, R ^1A is halogen (e.g., F, Cl, Br, or I). In embodiments, R ^1A is C _1-6 aliphatic. In embodiments, R ^1A is unsubstituted C _1-6 aliphatic. In embodiments, R ^1A is substituted C _1-6 aliphatic (e.g., comprising 1, 2, or 3 substituent groups). In embodiments, R ^1A is C _1-6 alkoxy. In embodiments, R ^1A is unsubstituted C _1-6 alkoxy. In embodiments, R ^1A is substituted C _1-6 alkoxy (e.g., comprising 1, 2, or 3 substituent groups). In embodiments, R ^1A is NR ⁶ R ⁷ . In embodiments, R ^1A is C(O)R ⁸ . In embodiments, R ^1A is CO ₂ R ⁸ . In embodiments, R ^1A is C(O)NR ⁶ R ⁷ . In embodiments, R ^1A is NR ⁹ C(O)R ⁸ . In embodiments, R ^1A is NR ⁹ CO ₂ R ⁸ . In embodiments, R ^1A is NR ⁹ C(O)NR ⁶ R ⁷ . In embodiments, R ^1A is R ¹⁰ . In embodiments, R ^1A is CH ₃ , CH ₂ F, CHF ₂ , or CF ₃ . In embodiments, R ^1A is CH ₃ . In embodiments, R ^1A is CH ₂ F, CHF ₂ , or CF ₃ . In embodiments, R ^1B is H. In embodiments, R ^1B is OH. In embodiments, R ^1B is CN. In embodiments, R ^1B is halogen (e.g., F, Cl, Br, or I). In embodiments, R ^1B is C _1-6 aliphatic. In embodiments, R ^1B is unsubstituted C _1-6 aliphatic. In embodiments, R ^1B is substituted C _1-6 aliphatic (e.g., comprising 1, 2, or 3 substituent groups). In embodiments, R ^1B is C _1-6 alkoxy. In embodiments, R ^1B is unsubstituted C _1-6 alkoxy. In embodiments, R ^1B is substituted C _1-6 alkoxy (e.g., comprising 1, 2, or 3 substituent groups). In embodiments, R ^1B is NR ⁶ R ⁷ . In embodiments, R ^1B is C(O)R ⁸ . In embodiments, R ^1B is CO ₂ R ⁸ . In embodiments, R ^1B is C(O)NR ⁶ R ⁷ . In embodiments, R ^1B is NR ⁹ C(O)R ⁸ . In embodiments, R ^1B is NR ⁹ CO ₂ R ⁸ . In embodiments, R ^1B is NR ⁹ C(O)NR ⁶ R ⁷ . In embodiments, R ^1B is R ¹⁰ . In embodiments, R ² is OH. In embodiments, R ² is CN. In embodiments, R ² is halogen (e.g., F, Cl, Br, or I). In embodiments, R ² is C _1-6 aliphatic (e.g., methyl). In embodiments, R ² is unsubstituted C _1-6 aliphatic (e.g., methyl). In embodiments, R ² is substituted C _1-6 aliphatic (e.g., comprising 1, 2, or 3 substituent groups). In embodiments, R ² is C _1-6 alkoxy. In embodiments, R ² is unsubstituted C _1-6 alkoxy. In embodiments, R ² is substituted C _1-6 alkoxy (e.g., comprising 1, 2, or 3 substituent groups). In embodiments, R ² is NR ⁶ R ⁷ . In embodiments, R ² is C(O)R ⁸ . In embodiments, R ² is CO ₂ R ⁸ . In embodiments, R ² is C(O)NR ⁶ R ⁷ . In embodiments, R ² is NR ⁹ C(O)R ⁸ . In embodiments, R ² is NR ⁹ CO ₂ R ⁸ . In embodiments, R ² is NR ⁹ C(O)NR ⁶ R ⁷ . In embodiments, R ² is R ¹⁰ . In embodiments, R ² is OR ¹⁰ . In embodiments, R ² is CH ₂ R ¹⁰ . In embodiments, R ² is CH ₂ CH ₂ R ¹⁰ . In embodiments, R ² is OCH ₂ R ¹⁰ . In embodiments, R ² is OCH ₂ CH ₂ R ¹⁰ . In embodiments, R ² is methyl. In embodiments, R ³ is–L ^P -E. In embodiments, R ³ is not –L ^P -E. In embodiments, R ³ further comprises -L ^P -E. In embodiments, R ³ is OH. In embodiments, R ³ is CN. In embodiments, R ³ is halogen (e.g., F, Cl, Br, or I). In embodiments, R ³ is C _1-6 aliphatic. In embodiments, R ³ is unsubstituted C _1-6 aliphatic. In embodiments, R ³ is substituted C _1-6 aliphatic (e.g., comprising 1, 2, or 3 substituent groups). In embodiments, R ³ is C _1-6 alkoxy. In embodiments, R ³ is unsubstituted C _1-6 alkoxy. In embodiments, R ³ is substituted C _1-6 alkoxy (e.g., comprising 1, 2, or 3 substituent groups). In embodiments, R ³ is NR ⁶ R ⁷ . In embodiments, R ³ is C(O)R ⁸ . In embodiments, R ³ is CO ₂ R ⁸ . In embodiments, R ³ is C(O)NR ⁶ R ⁷ . In embodiments, R ³ is NR ⁹ C(O)R ⁸ . In embodiments, R ³ is NR ⁹ CO ₂ R ⁸ . In embodiments, R ³ is NR ⁹ C(O)NR ⁶ R ⁷ . In embodiments, R ³ is R ¹⁰ . In embodiments, R ³ is OR ¹⁰ . In embodiments, R ³ is CH ₂ R ¹⁰ . In embodiments, R ³ is CH ₂ CH ₂ R ¹⁰ . In embodiments, R ³ is OCH ₂ R ¹⁰ . In embodiments, R ³ is OCH ₂ CH ₂ R ¹⁰ . In embodiments, R ³ is is halogen. In embodiments, R ³ is NR ⁶ R ⁷ , where R ⁶ and R ⁷ , together with the nitrogen atom to which they are attached, form a 5- to 6-membered heterocyclyl. In embodiments, R ³ is NR ⁶ R ⁷ , wherein each R ⁶ and R ⁷ is independently C ₁ -C ₆ alkyl (e.g., one R ⁶ and R ⁷ is unsubstituted C ₁ -C ₆ alkyl, and the other is C ₁ -C ₆ alkyl comprising an amino group, a monoalkylamino group, or a dialkylamino group). In embodiments, R ³ is unsubstituted or substituted phenyl or pyridyl. In embodiments, R ³ is unsubstituted or substituted phenyl. In embodiments, R ³ is unsubstituted or substituted pyridyl. In embodiments, R ³ is unsubstituted or substituted pyrrolidine, morpholine, piperidine, or piperazine. In embodiments, R ³ is C(O)R ⁸ , wherein R ⁸ is unsubstituted or substituted pyrrolidine, morpholine, piperidine, or piperazine. In embodiments, R ³ is R ¹⁰ , OR ¹⁰ , CH ₂ R ¹⁰ , CH ₂ CH ₂ R ¹⁰ , or OCH ₂ CH ₂ R ¹⁰ , wherein R ¹⁰ is unsubstituted or substituted pyrrolidine, morpholine, piperidine, or piperazine. In embodiments, R ³ is an unsubstituted group. In embodiments, R ³ is a group comprising 1, 2, 3, or 4 substituent groups. In embodiments, a substituent group is selected from halogen (e.g., F, Cl, Br, or I), C _1-6 aliphatic (e.g., methyl, monofluoromethyl, difluoromethyl, trifluoromethyl, ethyl, monofluoroethyl, propyl (e.g., n- propyl or isopropyl), butyl (e.g., n-butyl, sec-butyl, isobutyl, or tert-butyl)), amino ( ^_ NH ₂ ), monoalkylamino (e.g., -NHCH ₃ ), dialkylamino (e.g., -N(CH ₃ ) ₂ ), oxo (=O), C _3-6 cycloaliphatic (e.g., cyclopropyl, cyclobutyl, cyclopentyl, or cyclohexyl), or 3- to 6-membered heterocyclyl (e.g., oxetanyl, pyrrolidinyl, piperidinyl, piperazinyl, or morpholino), pyridyl, or phenyl. In embodiments, a cyclic group (e.g., a C _3-6 cycloaliphatic, a 3- to 6-membered heterocyclyl, a pyridyl, or a phenyl) comprises 1, 2, or 3 substituent groups (e.g., 1, 2, or 3 substituent groups selected from halogen (e.g., F, Cl, Br, or I), C _1-6 aliphatic (e.g., methyl, monofluoromethyl, difluoromethyl, trifluoromethyl, ethyl, monofluoroethyl, propyl (e.g., n-propyl or isopropyl), butyl (e.g., n-butyl, sec-butyl, isobutyl, or tert-butyl)), amino ( ^_ NH ₂ ), monoalkylamino (e.g., -NHCH ₃ ), dialkylamino (e.g., -N(CH ₃ ) ₂ ), and oxo (=O). In embodiments, R ⁴ is H. In embodiments, R ⁴ is an N-protecting group (e.g., an amide group, a carbamate group, or a sulfonamide group). In embodiments, R ⁴ is C _1-6 alkyl. In embodiments, a C _1-6 alkyl is unsubstituted. In embodiments, a C _1-6 alkyl is substituted (e.g., comprising 1, 2, or 3 substituent groups). In embodiments, R ⁵ is H. In embodiments, R ⁶ is H. In embodiments, R ⁶ is C _1-6 alkyl. In embodiments, a C _1-6 alkyl is unsubstituted. In embodiments, a C _1-6 alkyl is substituted (e.g., comprising 1, 2, or 3 substituent groups). In embodiments, R ⁷ is H. In embodiments, R ⁷ is C _1-6 alkyl. In embodiments, a C _1-6 alkyl is unsubstituted. In embodiments, a C _1-6 alkyl is substituted (e.g., comprising 1, 2, or 3 substituent groups). In embodiments, R ⁹ is H. In embodiments, R ⁹ is C _1-6 alkyl. In embodiments, a C _1-6 alkyl is unsubstituted. In embodiments, a C _1-6 alkyl is substituted (e.g., comprising 1, 2, or 3 substituent groups). In embodiments, R ⁶ and R ⁷ , together with the nitrogen atom to which they are attached, form a 3- to 10-membered heterocyclyl (e.g., monocyclic or bicyclic heterocyclyl). In embodiments, a 3- to 10-membered heterocyclyl is unsubstituted. In embodiments, a 3- to 10-membered heterocyclyl is substituted (e.g., comprising 1, 2, or 3 substituent groups). In embodiments, R ⁶ and R ⁹ , together with the atoms to which they are attached, form a 3- to 10-membered heterocyclyl (e.g., monocyclic or bicyclic heterocyclyl). In embodiments, a 3- to 10-membered heterocyclyl is unsubstituted. In embodiments, a 3- to 10-membered heterocyclyl is substituted (e.g., comprising 1, 2, or 3 substituent groups). In embodiments, R ⁸ is C _1-6 aliphatic. In embodiments, R ⁸ is C ₃ -C ₁₀ cycloaliphatic (e.g., monocyclic or bicyclic cycloaliphatic). In embodiments, R ⁸ is 3- to 10-membered heterocyclyl (e.g., monocyclic or bicyclic heterocyclyl). In embodiments, R ⁸ is phenyl. In embodiments, R ⁸ is naphthyl. In embodiments, R ⁸ is 5- to 12-membered heteroaryl (e.g., monocyclic or bicyclic heteroaryl). In embodiments, R ⁸ is unsubstituted C _1-6 aliphatic. In embodiments, R ⁸ is unsubstituted C ₃ -C ₁₀ cycloaliphatic. In embodiments, R ⁸ is unsubstituted 3- to 10-membered heterocyclyl. In embodiments, R ⁸ is unsubstituted phenyl. In embodiments, R ⁸ is unsubstituted naphthyl. In embodiments, R ⁸ is unsubstituted 5- to 12-membered heteroaryl. In embodiments, R ⁸ is substituted C _1-6 aliphatic. In embodiments, R ⁸ is substituted C ₃ -C ₁₀ cycloaliphatic. In embodiments, R ⁸ is substituted 3- to 10-membered heterocyclyl. In embodiments, R ⁸ is substituted phenyl. In embodiments, R ⁸ is substituted naphthyl. In embodiments, R ⁸ is substituted 5- to 12-membered heteroaryl. In embodiments, a substituted group comprises 1, 2, or 3 substituent groups as described herein. In embodiments, R ⁸ and R ⁹ , together with the atoms to which they are attached, form a 3- to 10-membered heterocyclyl (e.g., monocyclic or bicyclic heterocyclyl). In embodiments, a 3- to 10-membered heterocyclyl is unsubstituted. In embodiments, a 3- to 10-membered heterocyclyl is substituted (e.g., comprising 1, 2, or 3 substituent groups). In embodiments, R ¹⁰ is C ₃ -C ₁₀ cycloaliphatic (e.g., monocyclic or bicyclic cycloaliphatic). In embodiments, R ¹⁰ is 3- to 10-membered heterocyclyl (e.g., monocyclic or bicyclic heterocyclyl). In embodiments, R ¹⁰ is phenyl. In embodiments, R ¹⁰ is naphthyl. In embodiments, R ¹⁰ is 5- to 12-membered heteroaryl (e.g., monocyclic or bicyclic heteroaryl). In embodiments, R ¹⁰ is unsubstituted C ₃ -C ₁₀ cycloaliphatic. In embodiments, R ¹⁰ is unsubstituted 3- to 10-membered heterocyclyl. In embodiments, R ¹⁰ is unsubstituted phenyl. In embodiments, R ¹⁰ is unsubstituted naphthyl. In embodiments, R ¹⁰ is unsubstituted 5- to 12- membered heteroaryl. In embodiments, R ¹⁰ is substituted C ₃ -C ₁₀ cycloaliphatic. In embodiments, R ¹⁰ is substituted 3- to 10-membered heterocyclyl. In embodiments, R ¹⁰ is substituted phenyl. In embodiments, R ¹⁰ is substituted naphthyl. In embodiments, R ¹⁰ is substituted 5- to 12-membered heteroaryl. In embodiments, a substituted group comprises 1, 2, or 3 substituent groups as described herein. In embodiments, n is 0. In embodiments, n is 1. In embodiments, n is 2. In embodiments, n is 1 or 2. In embodiments, o is 0. In embodiments, o is 1. In embodiments, o is 2. In embodiments, o is 1 or 2. [0142] In embodiments, a compound of the invention comprising a Class B ligand has a structure selected from the following formulas selected from Table B1. In embodiments, an E moiety is selected from those described in Table D, where shows the point of covalent attachment to moiety L ^P . In embodiments, -L ^P -E is according to any of substructures (D1)- (D49) as described herein. In embodiments, -L ^P -E is according to any of substructures (D1)’- (D49)’ as described herein. Table B1. Exemplary Formulas Comprising Class B Ligands or a pharmaceutically acceptable salt thereof. [0143] In embodiments, the compound is according to Formula (BIX), (BX), or (BXI), or a pharmaceutically acceptable salt thereof, wherein L ¹ is C ₁ -C ₆ alkylene optionally substituted by 1, 2, or 3 R ¹³ ; each R ¹³ is independently unsubstituted C ₁ -C ₃ alkyl; and R ^1A is independently unsubstitued C ₁ -C ₆ alkyl or C ₁ -C ₆ haloalkyl. [0144] In embodiments, the compound is according to Formula (BXII), or a pharmaceutically acceptable salt thereof, wherein R ^1A is independently unsubstitued C ₁ -C ₆ alkyl or C ₁ -C ₆ haloalkyl. [0145] In embodiments, the compound is according to Formula (BXIII) or (BXIV), or a pharmaceutically acceptable salt thereof, wherein L ¹ is C ₁ -C ₆ alkylene optionally substituted by 1 or 2 R ¹³ ; each R ¹³ is independently unsubstituted C ₁ -C ₃ alkyl; and R ^1A is independently unsubstitued C ₁ -C ₆ alkyl or C ₁ -C ₆ haloalkyl. [0146] In embodiments, L ¹ is selected from: –(CH ₂ ) ₃ –; –(CH ₂ ) ₄ –; wherein a carbon marked by an asterisk (*) is racemic or has the (R)- or (S)- stereochemistry. In embodiments, a carbon marked by an asterisk (*) is racemic. In embodiments, a carbon marked by an asterisk (*) has the (R)-stereochemistry. In embodiments, a carbon marked by an asterisk (*) has the (S)-stereochemistry. [0001] In embodiments, -L ¹ -L ² -X ¹ - or -L ¹ -L ² -X ^1A - is [0002] In embodiments, -L ¹ -L ² -X ¹ - or -L ¹ -L ² -X ^1A - is [0003] In embodiments, -L ¹ -L ² -X ¹ - or -L ¹ -L ² -X ^1A - is [0004] In embodiments, -L ¹ -L ² -X ¹ - or -L ¹ -L ² -X ^1A - is [0005] In embodiments, -L ¹ -L ² -X ¹ - or -L ¹ -L ² -X ^1A - is substructure (S1). In embodiments, - L ¹ -L ² -X ¹ - or -L ¹ -L ² -X ^1A - is substructure (S2). In embodiments, -L ¹ -L ² -X ¹ - or -L ¹ -L ² -X ^1A - is substructure (S3). In embodiments, -L ¹ -L ² -X ¹ - or -L ¹ -L ² -X ^1A - is substructure (S4). In embodiments, -L ¹ -L ² -X ¹ - or -L ¹ -L ² -X ^1A - is substructure (S5). In embodiments, -L ¹ -L ² -X ¹ - or - L ¹ -L ² -X ^1A - is substructure (S6). In embodiments, -L ¹ -L ² -X ¹ - or -L ¹ -L ² -X ^1A - is substructure (S7). In embodiments, -L ¹ -L ² -X ¹ - or -L ¹ -L ² -X ^1A - is substructure (S8). [0147] In embodiments, the compound comprises a ligand formed from any one Compounds (1)-(71) of PCT/US22/21999, or a pharmaceutically acceptable salt thereof. [0148] In embodiments, the compound comprises a ligand derived from any one of Compounds (1)-(71) of PCT/US22/21999, or a pharmaceutically acceptable salt thereof. In embodiments, the compound of PCT/US22/21999 is modified to include a piperazine- or piperazine-containing group covalently attached to the -L ^P -E group as described herein. [0149] In embodiments, the compound is selected from any of the following compounds of Table B2, or a pharmaceutically acceptable salt thereof. In embodiments, an E moiety is selected from those described in Table D, where shows the point of covalent attachment to moiety L ^P . In embodiments, -L ^P -E is according to any of substructures (D1)-(D49) as described herein. Table B2. Exemplary Compounds Comprising Class B Ligands

Exemplary Compounds Comprising a Class C Ligand [0150] In embodiments, the invention features compounds comprising a Class C ligand. In embodiments, a compound of the invention as described herein comprises or is derived from a Class C ligand, wherein said ligand is according to or derived from any one of Formulas (I), (II), (III), (IV), (V), (VI), (VII), (VIII), (IX), (X), (XI), (XII), (XIII), (XIV), (XV), (XVI), (XVII), (XVIII), (XIX), (XX), (XXI), (XXII), and (XXIII) as described in PCT/US22/28755, such as any one of Compounds (1)-(169), or a pharmaceutically acceptable salt thereof. [0151] Certain exemplary structure features are described herein. Exemplary structural formulae and compounds can feature any combination of features as described herein. [0152] In embodiments of compounds comprising or derived from a Class C Ligand, E and L ^P are according to any embodiments described herein, as well as any combinations thereof. [0153] In one embodiment, the invention features a compound having a structure according to Formula (CI), or a pharmaceutically acceptable salt thereof, wherein X ² is independently N or CR ⁵ ; each of X ³ and X ⁴ is independently a covalent bond, O, S, NR ⁶ , C(O)NR ⁶ , NR ⁶ C(O), NR ⁶ C(O)NR ⁶ , or (C(R ⁷ ) ₂ ) _q ; L ¹ is independently a covalent bond, C _1-6 heteroalkylene, C _1-6 alkylene, C _2-6 alkenylene, C _2-6 alkynylene, C _3-6 cycloalkylene, 3- to 10-membered heterocyclylene, phenylene, naphthylene, or 5- to 10-membered heteroarylene; each R ¹ is independently L ^P -E, (Substructure A), OH, CN, halogen, C _1-6 aliphatic, C _1-6 alkoxy, NR ⁸ R ⁹ , C(O)R ¹⁰ , CO ₂ R ¹⁰ , C(O)NR ⁸ R ⁹ , NR ¹¹ C(O)R ¹⁰ , NR ¹¹ CO ₂ R ¹⁰ , NR ¹¹ C(O)NR ⁸ R ⁹ , or (CH ₂ )rR ¹² , or two R ¹ or two R ² , together to which the atoms they are attached form a 5- to 10-membered ring, and where valency permits when R ¹ is not –L ^P -E, R ¹ optionally further comprises –L ^P -E; each R ² is independently L ^P -E, (Substructure A), OH, CN, halogen, C _1-6 aliphatic, C _1-6 alkoxy, NR ⁸ R ⁹ , C(O)R ¹⁰ , CO ₂ R ¹⁰ , C(O)NR ⁸ R ⁹ , NR ¹¹ C(O)R ¹⁰ , NR ¹¹ CO ₂ R ¹⁰ , NR ¹¹ C(O)NR ⁸ R ⁹ , or (CH ₂ )rR ¹² , or two R ¹ or two R ² , together to which the atoms they are attached form a 5- to 10-membered ring, and where valency permits when R ² is not –L ^P -E, R ² optionally further comprises –L ^P -E; L ^P is a linker; E is an E3 ubiquitin ligase ligand; L ² is independently a covalent bond, O, NR ^L , C(O), C(O)NR ^L , NR ^L C(O), CR ^L ₂ ; R ^L is independently H or C _1-6 alkyl; A is independently phenyl, naphthyl, 5- to 13-membered heteroaryl, C ₃ -C ₁₀ cycloaliphatic, or 3- to 10-membered heterocyclyl; B is independently phenyl, naphthyl, 5- to 13-membered heteroaryl, C ₃ -C ₁₀ cycloaliphatic, or 3- to 10-membered heterocyclyl; C is independently 5- or 6-membered heteroaryl; each R ³ is independently OH, CN, halogen, C _1-6 aliphatic, C _1-6 alkoxy, NR ⁸ R ⁹ , C(O)R ¹⁰ , CO ₂ R ¹⁰ , C(O)NR ⁸ R ⁹ , NR ¹¹ C(O)R ¹⁰ , NR ¹¹ CO ₂ R ¹⁰ , NR ¹¹ C(O)NR ⁸ R ⁹ , or (CH ₂ ) _r R ¹² ; each R ⁴ is independently –L ^P -E, H, OH, CN, halogen, C _1-6 aliphatic, C _1-6 alkoxy, NR ⁸ R ⁹ , C(O)R ¹⁰ , CO ₂ R ¹⁰ , C(O)NR ⁸ R ⁹ , NR ¹¹ C(O)R ¹⁰ , NR ¹¹ CO ₂ R ¹⁰ , NR ¹¹ C(O)NR ⁸ R ⁹ , NR ¹¹ (CH ₂ ) _s NR ⁸ R ⁹ , (CH ₂ ) _t NR ⁸ R ⁹ , (CH ₂ ) _t OH, (CH ₂ ) _t OCH ₃ , O(CH ₂ ) _t OH, O(CH ₂ ) _t OCH ₃ , O(CH ₂ ) _r R ¹² , or (CH ₂ ) _r R ¹² ; or R ⁴ and R ⁶ or R ⁴ and R ⁷ , together with the atoms to which they are attached, form a 5- to 6-membered ring, and where valency permits when R ⁴ is not –L ^P -E, R ⁴ optionally further comprises –L ^P -E; each R ⁵ is independently H, OH, CN, halogen, C _1-6 aliphatic, C _1-6 alkoxy, NR ⁸ R ⁹ , C(O)R ¹⁰ , CO ₂ R ¹⁰ , C(O)NR ⁸ R ⁹ , NR ¹¹ C(O)R ¹⁰ , NR ¹¹ CO ₂ R ¹⁰ , NR ¹¹ C(O)NR ⁸ R ⁹ , or (CH ₂ )rR ¹² ; each R ⁶ is independently H, a N-protecting group, or C _1-6 alkyl; or R ⁶ and R ⁴ , together with the atoms to which they are attached, form a 5- to 6-membered ring; each R ⁷ is independently H or C _1-6 alkyl; or two R ⁷ on the same carbon combine to from an oxo (=O) group; or R ⁷ and R ⁴ , together with the atoms to which they are attached, form a 5- to 6-membered ring; each R ⁸ , R ⁹ , and R ¹¹ is independently H or C _1-6 alkyl; or R ⁸ and R ⁹ , together with the nitrogen atom to which they are attached, form a 3- to 10-membered heterocyclyl, or R ⁸ and R ¹¹ , together with the atoms to which they are attached, form a 3- to 10-membered heterocyclyl; each R ¹⁰ is independently C _1-6 aliphatic, C ₃ -C ₁₀ cycloaliphatic, 3- to 10-membered heterocyclyl, phenyl, naphthyl, or a 5- to 12-membered heteroaryl; or R ¹⁰ and R ¹¹ , together with the atoms to which they are attached, form a 3- to 10-membered heterocyclyl; each R ¹² is independently C ₃ -C ₁₀ cycloaliphatic, 3- to 10-membered heterocyclyl, phenyl, naphthyl, or a 5- to 12-membered heteroaryl; each m, n, and o is independently 0, 1, or 2; each p is independently 0, 1, 2; 3, or 4; each q is independently 1 or 2; each r is independently an integer of 0-4; each s is independently an integer of 2-6; each t is independently an integer of 1-6; and wherein the compound comprises one and only one L ^P -E moiety. In embodiments, each R ⁴ is independently H, OH, CN, halogen, C _1-6 aliphatic, C _1-6 alkoxy, NR ⁸ R ⁹ , C(O)R ¹⁰ , CO ₂ R ¹⁰ , C(O)NR ⁸ R ⁹ , NR ¹¹ C(O)R ¹⁰ , NR ¹¹ CO ₂ R ¹⁰ , NR ¹¹ C(O)NR ⁸ R ⁹ , NR ¹¹ (CH ₂ ) _s NR ⁸ R ⁹ , (CH ₂ ) _t NR ⁸ R ⁹ , or (CH ₂ ) _r R ¹² ; or R ⁴ and R ⁶ , or R ⁴ and R ⁷ , together with the atoms to which they are attached, form a 5- to 6-membered ring. In embodiments, m is 0. In embodiments, m is 1. In embodiments, m is 2. In embodiments, m is 1 or 2. In embodiments, n is 0. In embodiments, n is 1. In embodiments, n is 2. In embodiments, n is 1 or 2. In embodiments, m is not 0. In embodiments, n is not 0. In embodiments, at least one m or n is not 0. In embodiments, m is 1, and n is 0. In embodiments, n is 1, and m is 0. In embodiments, p is 0. In embodiments, p is 1. In embodiments, p is 2. In embodiments, p is 3. In embodiments, p is 4. In embodiments, R ¹ is present. In embodiments, R ² is present. In embodiments, at least one of R ¹ and R ² is present. In embodiments, one of R ¹ and R ² is present. In embodiments, no more than one of R ¹ and R ² is present. In embodiments, one of R ¹ and R ² is present and is Substructure A ( ) or halogen (e.g., F, Cl, Br, or I). In embodiments, one of R ¹ and R ² is present and is Substructure A ( ). In embodiments, Substructure A ( ) is not present. In embodiments, one Substructure A group is present. In embodiments, no more than one Substructure A is present. In embodiments, two Substructure A groups are present (e.g., two Substructure A groups with identical or different structures). In embodiments, more than two Substructure A groups are present (e.g., more than two Substructure A groups with identical or different structures). In embodiments, no more than one Substructure A group is present. In embodiments, C is 5- or 6-membered N-containing heteroaryl. In embodiments, C is pyridyl, pyrimidyl, pyrazolyl, pyrrolyl, thiazolyl, oxazolyl, or imidazolyl. In embodiments, A is pyridyl, pyrimidyl, pyrazolyl, pyrrolyl, thiazolyl, oxazolyl, or imidazolyl. In embodiments, B is pyridyl, pyrimidyl, pyrazolyl, pyrrolyl, thiazolyl, oxazolyl, or imidazolyl. In embodiments, each of A and B is pyrazolyl. In embodiments, In embodiments, A is pyridyl or pyrimidyl. In embodiments, X ¹ is N. In embodiments, X ² is CR ⁵ (e.g., CH). In embodiments, X ² is N. In embodiments, X ² is CR ⁵ (e.g., CH). In embodiments, X ³ is a covalent bond. In embodiments, X ³ is O. In embodiments, X ³ is S. In embodiments, X ³ is NR ⁶ , C(O)NR ⁶ , NR ⁶ C(O), or NR ⁶ C(O)NR ⁶ . In embodiments, R ⁶ is H. In embodiments, R ⁶ is an N-protecting group (e.g., an amide group, a carbamate group, or a sulfonamide group). In embodiments, R ⁶ is C _1-6 alkyl. In embodiments, a C _1-6 alkyl is unsubstituted. In embodiments, a C _1-6 alkyl is substituted (e.g., comprising 1, 2, or 3 substituent groups). In embodiments, X ³ is (C(R ⁷ ) ₂ ) _q . In embodiments, q is 1. In embodiments, q is 2. In embodiments, R ⁷ is H. In embodiments, R ⁷ is C _1-6 alkyl. In embodiments, a C _1-6 alkyl is unsubstituted. In embodiments, a C _1-6 alkyl is substituted (e.g., comprising 1, 2, or 3 substituent groups). In embodiments, two R ⁷ on the same carbon combine to from an oxo (=O) group. In embodiments, X ³ is C(O), CH ₂ , CHCH ₃ , or C(CH ₃ ) ₂ . In embodiments, X ⁴ is a covalent bond. In embodiments, X ⁴ is O. In embodiments, X ⁴ is S. In embodiments, X ⁴ is NR ⁶ , C(O)NR ⁶ , NR ⁶ C(O), or NR ⁶ C(O)NR ⁶ . In embodiments, R ⁶ is H. In embodiments, R ⁶ is an N-protecting group (e.g., an amide group, a carbamate group, or a sulfonamide group). In embodiments, R ⁶ is C _1-6 alkyl. In embodiments, a C _1-6 alkyl is unsubstituted. In embodiments, a C _1-6 alkyl is substituted (e.g., comprising 1, 2, or 3 substituent groups). In embodiments, X ⁴ is (C(R ⁷ ) ₂ ) _q . In embodiments, q is 1. In embodiments, q is 2. In embodiments, R ⁷ is H. In embodiments, R ⁷ is C _1-6 alkyl. In embodiments, a C _1-6 alkyl is unsubstituted. In embodiments, a C _1-6 alkyl is substituted (e.g., comprising 1, 2, or 3 substituent groups). In embodiments, two R ⁷ on the same carbon combine to from an oxo (=O) group. In embodiments, X ⁴ is C(O), CH ₂ , CHCH ₃ , or C(CH ₃ ) ₂ . In embodiments, X ³ is O and X ⁴ is O. In embodiments, X ² is CH, X ³ is O, and X ⁴ is O. In embodiments, X ¹ is N. In embodiments, R ⁶ and R ⁴ , together with the atoms to which they are attached, form a 5- to 6-membered ring. In embodiments, a 5- to 6-membered ring has a structure of where the M ring is the newly-formed ^A ring. In embodiments, L is a covalent bond. In embodiments, L ^A is an alkylene (e.g., -CH ₂ -). In embodiments, an alkylene is unsubstituted. In embodiments, an alkylene is substituted (e.g., comprising 1 or 2 substituent groups). In embodiments, R ⁷ and R ⁴ , together with the atoms to which they are attached, form a 5- to 6-membered ring. In embodiments, a 5- to 6-membered ring has a structure of where the M ring is the newly-formed ring. In embodiments, L ^A is a covalent bond. In embodiments, L ^A is an alkylene (e.g., -CH ₂ -). In embodiments, an alkylene is unsubstituted. In embodiments, an alkylene is substituted (e.g., comprising 1 or 2 substituent groups). In embodiments, X ³ and X ⁴ are the same. In embodiments, X ³ and X ⁴ are different. In embodiments, X ³ and X ⁴ are both O. In embodiments, L ¹ is a covalent bond. In embodiments, L ¹ is a C _1-6 heteroalkylene (e.g., comprises 1, 2, or 3 heteroatoms that are independently oxygen or nitrogen). In embodiments, L ¹ is a branched C _1-6 heteroalkylene. In embodiments, L ¹ is a linear C _1-6 heteroalkylene. In embodiments, L ¹ is unsubstituted C _1-6 heteroalkylene. In embodiments, L ¹ is unsubstituted branched C _1-6 heteroalkylene. In embodiments, L ¹ is unsubstituted linear C _1-6 heteroalkylene. In embodiments, L ¹ is substituted C _1-6 heteroalkylene (e.g., comprising 1, 2, or 3 substituent groups such as OH, oxo (=O), or unsubstituted C _1-3 alkyl). In embodiments, L ¹ is substituted branched C _1-6 heteroalkylene (e.g., comprising 1, 2, or 3 substituent groups such as OH, oxo (=O), or unsubstituted C _1-3 alkyl). In embodiments, L ¹ is substituted linear C _1-6 heteroalkylene (e.g., comprising 1, 2, or 3 substituent groups such as OH, oxo (=O), or unsubstituted C _1-3 alkyl). In embodiments, a C _1-6 heteroalkylene is -O(CH ₂ )u-, - (CH ₂ )uO-, -O(CH ₂ )uO-, -OCH ₂ OCH ₂ CH ₂ OCH ₂ –, -CH ₂ OCH ₂ CH ₂ O-, -OCH ₂ CH ₂ OCH ₂ - , -NH(CH ₂ ) _u -, - (CH ₂ ) _u NH-, or -NH(CH ₂ ) _u NH-, and wherein u is an integer of 1-4. In embodiments, u is 1. In embodiments, u is 2. In embodiments, u is 3. In embodiments, u is 4. In embodiments, L ¹ is a C _1-6 alkylene (e.g., CH ₂ , (CH ₂ ) ₂ , (CH ₂ ) ₃ , (CH ₂ ) ₄ , (CH ₂ ) ₅ , or (CH ₂ ) ₆ ). In embodiments, L ¹ is a branched C _1-6 alkylene. In embodiments, L ¹ is a linear C _1-6 alkylene. In embodiments, L ¹ is unsubstituted C _1-6 alkylene. In embodiments, L ¹ is unsubstituted branched C _1-6 alkylene. In embodiments, L ¹ is unsubstituted linear C _1-6 alkylene. In embodiments, L ¹ is substituted C _1-6 alkylene (e.g., comprising 1, 2, or 3 substituent groups such as OH, oxo (=O), or unsubstituted C _1-3 alkyl). In embodiments, L ¹ is substituted branched C _1-6 alkylene (e.g., comprising 1, 2, or 3 substituent groups such as OH, oxo (=O), or unsubstituted C _1-3 alkyl). In embodiments, L ¹ is substituted linear C _1-6 alkylene (e.g., comprising 1, 2, or 3 substituent groups such as OH, oxo (=O), or unsubstituted C _1-3 alkyl). In embodiments, L ¹ is unsubstituted C _1-6 alkylene. In embodiments, L ¹ is unsubstituted branched C _2-6 alkylene. In embodiments, L ¹ is unsubstituted linear C _2-6 alkylene. In embodiments, L ¹ is a C _2-6 alkenylene (e.g., C ₂ H ₄ , C ₃ H ₆ , C ₄ H ₈ , C ₅ H ₁₀ , or C ₆ H ₁₂ ). In embodiments, L ¹ is unsubstituted C _2-6 alkenylene. In embodiments, L ¹ is substituted C _2-6 alkenylene (e.g., comprising 1, 2, or 3 substituent groups). In embodiments, L ¹ is a C _2-6 alkynylene (e.g., C ₂ H ₂ , C ₃ H ₄ , C ₄ H ₆ , C ₅ H ₈ , or C ₆ H ₁₀ ). In embodiments, L ¹ is unsubstituted C _2-6 alkynylene. In embodiments, L ¹ is substituted C _2-6 alkynylene (e.g., comprising 1, 2, or 3 substituent groups). In embodiments, L ¹ is a C _3-6 cycloalkylene (e.g., cyclopropylene, cyclobutylene, cyclopentylene, or cyclohexylene). In embodiments, L ¹ is unsubstituted C _3-6 cycloalkylene. In embodiments, L ¹ is substituted C _3-6 cycloalkylene (e.g., comprising 1, 2, or 3 substituent groups). In embodiments, the sp ³ carbon of a L ¹ group has the (R)-configuration. In embodiments, the sp ³ carbon of a L ¹ group has the (S)-configuration. In embodiments, L ¹ is a 3- to 10-membered heterocyclylene (e.g., monocyclic or bicyclic heterocyclylene). In embodiments, L ¹ is unsubstituted 3- to 10-membered heterocyclylene. In embodiments, L ¹ is substituted 3- to 10-membered heterocyclylene (e.g., comprising 1, 2, or 3 substituent groups). In embodiments, L ¹ is a phenylene or naphthylene. In embodiments, L ¹ is unsubstituted phenylene or unsubstituted naphthylene. In embodiments, L ¹ is substituted phenylene or substituted naphthylene (e.g., comprising 1, 2, or 3 substituent groups). In embodiments, L ¹ is a 5- to 10-membered heteroarylene. In embodiments, L ¹ is unsubstituted 5- to 10-membered heteroarylene. In embodiments, L ¹ is substituted 5- to 10-membered heteroarylene (e.g., comprising 1, 2, or 3 substituent groups). In embodiments, L ¹ is an unsubstituted linear C _4-6 alkylene or an unsubstituted branched C _4-6 alkylene. In embodiments, L ¹ is -(CH ₂ ) ₃ -. In embodiments, L ¹ is -CH(CH ₃ )CH ₂ CH ₂ -. In embodiments, L ¹ is In embodiments, L ¹ is where * denotes the point of covalent attachment to X ⁴ , and ** denotes the point of covalent attachment to X ³ . In embodiments, -X ⁴ -L ¹ -X ³ - is -O-L ¹ -O-. In embodiments, -X ⁴ -L ¹ -X ³ - is -O(CH ₂ ) ₃ O-. In embodiments, -X ⁴ -L ¹ -X ³ - is -OCH(CH ₃ )CH ₂ CH ₂ O-. In embodiments, -X ⁴ -L ¹ -X ³ - is In embodiments, X ⁴ -L ¹ -X ³ forms or comprises a urea group (e.g., NHC(O)NH). In embodiments, X ³ and/or X ⁴ is NR ⁶ C(O)NR ⁶ . In embodiments, one of X ³ and X ⁴ is NR ⁶ C(O)NR ⁶ . In embodiments, X ⁴ -L ¹ -X ³ forms or comprises a carboxamide group (e.g., C(O)NH or NH(CO)). In embodiments, X ³ and/or X ⁴ is C(O)NR ⁶ or NR ⁶ C(O). In embodiments, one of X ³ and X ⁴ is C(O)NR ⁶ or NR ⁶ C(O). In embodiments, X ⁴ -L ¹ -X ³ is -CHR ⁷ -O(C _1-2 alkylene)-OCHR ⁷ - or -CHR ⁷ -O(C _1-2 alkylene)-O-. In embodiments, B is phenyl. In embodiments, B is naphthyl. In embodiments, B is 5- to 13- membered heteroaryl (e.g., monocyclic or bicyclic heteroaryl). In embodiments, B is a bicyclic 8- to 12-membered heteroaryl (e.g., nitrogen-containing, bicyclic 8- to 12-membered heteroaryl). In embodiments, B is a monocyclic 5- to 6-membered heteroaryl. Examplary monocyclic 5- to 6-membered heteroaryls include but are not limited to pyridyl, pyrimidyl, pyrazolyl, pyrrolyl, thiazolyl, oxazolyl, and imidazolyl. In embodiments, B is phenyl or 5- to 6-membered heteroaryl. In embodiments, B is phenyl, pyridyl, pyrimidyl, pyrazolyl, pyrrolyl, thiazolyl, oxazolyl, or imidazolyl. In embodiments, B is pyrazolyl. In embodiments, B is unsubstituted phenyl. In embodiments, B is unsubstituted naphthyl. In embodiments, B is unsubstituted 5- to 13-membered heteroaryl (e.g., unsubstituted monocyclic or bicyclic heteroaryl). In embodiments, B is unsubstituted bicyclic 8- to 12- membered heteroaryl (e.g., unsubstituted nitrogen-containing, bicyclic 8- to 12-membered heteroaryl). In embodiments, B is unsubstituted monocyclic 5- to 6-membered heteroaryls. In embodiments, B is unsubstituted pyridyl, unsubstituted pyrimidyl, unsubstituted pyrazolyl, unsubstituted pyrrolyl, unsubstituted thiazolyl, unsubstituted oxazolyl, or unsubstituted imidazolyl. In embodiments, B is substituted phenyl (e.g., comprising 1 or 2 substituents as described herein). In embodiments, B is substituted naphthyl (e.g., comprising 1 or 2 substituents as described herein). In embodiments, B is substituted 5- to 13-membered heteroaryl (e.g., substituted monocyclic or bicyclic heteroaryl comprising 1 or 2 substituents as described herein). B is substituted bicyclic 8- to 12-membered heteroaryl (e.g., substituted nitrogen- containing, bicyclic 8- to 12-membered heteroaryl). In embodiments, B is substituted monocyclic 5- to 6-membered heteroaryls. In embodiments, B is substituted pyridyl, substituted pyrimidyl, substituted pyrazolyl, substituted pyrrolyl, substituted thiazolyl, substituted oxazolyl, or substituted imidazolyl. In embodiments, B is substituted pyrazolyl (e.g., N-substituted pyrazolyl such as N-methyl pyrazolyl). In embodiments, B is substituted with one or more R ³ groups as described herein (e.g., methyl, halogen, or CN). In embodiments, B is where * denotes the point of covalent attachment to C, and ** denotes the point of covalent attachment to X ³ . In embodiments, C is 5- or 6-membered heteroaryl. In embodiments, C is 5- or 6-membered N-containing heteroaryl. Examplary 5- or 6-membered heteroaryls include but are not limited to pyridyl, pyrimidyl, pyrazolyl, pyrrolyl, thiazolyl, oxazolyl, and imidazolyl. In embodiments, C is pyridyl or pyrimidyl. In embodiments, C is pyrazolyl or thiazolyl. In embodiments, C is unsubstituted 5- or 6-membered heteroaryl. In embodiments, C is unsubstituted 5- or 6-membered N-containing heteroaryl. Examplary unsubstituted 5- or 6-membered heteroaryls include but are not limited to unsubstituted pyridyl, unsubstituted pyrimidyl, unsubstituted pyrazolyl, unsubstituted pyrrolyl, unsubstituted thiazolyl, unsubstituted oxazolyl, and unsubstituted imidazolyl. In embodiments, C is unsubstituted pyridyl or pyrimidyl. In embodiments, C is unsubstituted pyrazolyl or thiazolyl. In embodiments, C is substituted 5- or 6-membered heteroaryl (e.g., comprising 1 or 2 substituents as described herein). In embodiments, C is substituted 5- or 6-membered N- containing heteroaryl (e.g., comprising 1 or 2 substituents as described herein). In embodiments, C is substituted pyridyl, substituted pyrimidyl, substituted pyrazolyl, substituted pyrrolyl, substituted thiazolyl, substituted oxazolyl, or substituted imidazolyl. In embodiments, C is substituted pyridyl (e.g., substituted with Substructure A). In embodiments, C is substituted pyrimidyl (e.g., substituted with Substructure A). In embodiments, C is substituted pyrazolyl (e.g., N-substituted pyrazolyl such as N-methyl pyrazolyl). In embodiments, C is substituted thiazolyl (e.g., methyl substituted thiazolyl). In embodiments, C is substituted with one or more R ¹ groups as described herein (e.g., Substructure A or methyl). In embodiments, A is pyrazolyl, B is pyrazolyl, and C is pyridyl or pyrimidyl. In embodiments, A and B are substituted. In embodiments, m is 0. In embodiments, m is 1. In embodiments, m is 2. In embodiments, m is 1 or 2. In embodiments, m is not 0. In embodiments, R ¹ is present. In embodiments, R ¹ is (Substructure A). In embodiments, L ² is independently a covalent bond, O, NR ^L , C(O), C(O)NR ^L , NR ^L C(O), CR ^L ₂ , wherein R ^L is independently H or C _1-6 alkyl. In embodiments, R ^L is unsubstituted C _1-6 alkyl. In embodiments, R ^L is substituted C _1-6 alkyl (e.g., comprising 1, 2, or 3 substituent groups). In embodiments, L ² is covalent bond. In embodiments, each R ⁴ is independently H, OH, CN, halogen, C _1-6 aliphatic, C _1-6 alkoxy, NR ⁸ R ⁹ , C(O)R ¹⁰ , CO ₂ R ¹⁰ , C(O)NR ⁸ R ⁹ , NR ¹¹ C(O)R ¹⁰ , NR ¹¹ CO ₂ R ¹⁰ , NR ¹¹ C(O)NR ⁸ R ⁹ , NR ¹¹ (CH ₂ ) _s NR ⁸ R ⁹ , (CH ₂ ) _t NR ⁸ R ⁹ , or (CH ₂ ) _r R ¹² . In embodiments, p is 0. In embodiments, p is 1. In embodiments, p is 2. In embodiments, R ⁴ is–L ^P -E. In embodiments, R ⁴ is not –L ^P -E. In embodiments, R ⁴ further comprises -L ^P -E. In embodiments, R ¹ is–L ^P -E. In embodiments, R ¹ is not –L ^P -E. In embodiments, R ¹ further comprises -L ^P -E. In embodiments, R ¹ is OH. In embodiments, R ¹ is CN. In embodiments, R ¹ is halogen (e.g., F, Cl, Br, or I). In embodiments, R ¹ is C _1-6 aliphatic. In embodiments, R ¹ is unsubstituted C _1-6 aliphatic. In embodiments, R ¹ is substituted C _1-6 aliphatic (e.g., comprising 1, 2, or 3 substituent groups). In embodiments, R ¹ is C _1-6 alkoxy. In embodiments, R ¹ is unsubstituted C _1-6 alkoxy. In embodiments, R ¹ is substituted C _1-6 alkoxy (e.g., comprising 1, 2, or 3 substituent groups). In embodiments, R ¹ is NR ⁸ R ⁹ . In embodiments, R ¹ is C(O)R ¹⁰ . In embodiments, R ¹ is CO ₂ R ¹⁰ . In embodiments, R ¹ is C(O)NR ⁸ R ⁹ . In embodiments, R ¹ is NR ¹¹ C(O)R ¹⁰ . In embodiments, R ¹ is NR ¹¹ CO ₂ R ¹⁰ . In embodiments, R ¹ is NR ¹¹ C(O)NR ⁸ R ⁹ . In embodiments, R ¹ is (CH ₂ ) _r R ¹² . In embodiments, r is 0. In embodiments, r is 1. In embodiments, r is 2. In embodiments, r is 3. In embodiments, r is 4. In embodiments, r is 0 or 1. In embodiments, R ¹ is halogen (e.g., F, Cl, Br, or I). In embodiments, n is 0. In embodiments, n is 1. In embodiments, n is 2. In embodiments, n is 1 or 2. In embodiments, n is not 0. In embodiments, R ² is present. In embodiments, R ² is (Substructure A). In embodiments, L ² is independently a covalent bond, O, NR ^L , C(O), C(O)NR ^L , NR ^L C(O), CR ^L 2, wherein R ^L is independently H or C _1-6 alkyl. In embodiments, R ^L is unsubstituted C _1-6 alkyl. In embodiments, R ^L is substituted C _1-6 alkyl (e.g., comprising 1, 2, or 3 substituent groups). In embodiments, L ² is covalent bond. In embodiments, each R ⁴ is independently H, OH, CN, halogen, C _1-6 aliphatic, C _1-6 alkoxy, NR ⁸ R ⁹ , C(O)R ¹⁰ , CO ₂ R ¹⁰ , C(O)NR ⁸ R ⁹ , NR ¹¹ C(O)R ¹⁰ , NR ¹¹ CO ₂ R ¹⁰ , NR ¹¹ C(O)NR ⁸ R ⁹ , NR ¹¹ (CH ₂ ) _s NR ⁸ R ⁹ , (CH ₂ ) _t NR ⁸ R ⁹ , or (CH ₂ )rR ¹² . In embodiments, p is 0. In embodiments, p is 1. In embodiments, p is 2. In embodiments, R ⁴ is–L ^P -E. In embodiments, R ⁴ is not –L ^P -E. In embodiments, R ⁴ further comprises -L ^P -E. In embodiments, R ² is–L ^P -E. In embodiments, R ² is not –L ^P -E. In embodiments, R ² further comprises -L ^P -E. In embodiments, R ² is OH. In embodiments, R ² is CN. In embodiments, R ² is halogen (e.g., F, Cl, Br, or I). In embodiments, R ² is C _1-6 aliphatic. In embodiments, R ² is unsubstituted C _1-6 aliphatic. In embodiments, R ² is substituted C _1-6 aliphatic (e.g., comprising 1, 2, or 3 substituent groups). In embodiments, R ² is C _1-6 alkoxy. In embodiments, R ² is unsubstituted C _1-6 alkoxy. In embodiments, R ² is substituted C _1-6 alkoxy (e.g., comprising 1, 2, or 3 substituent groups). In embodiments, R ² is NR ⁸ R ⁹ . In embodiments, R ² is C(O)R ¹⁰ . In embodiments, R ² is CO ₂ R ¹⁰ . In embodiments, R ² is C(O)NR ⁸ R ⁹ . In embodiments, R ² is NR ¹¹ C(O)R ¹⁰ . In embodiments, R ² is NR ¹¹ CO ₂ R ¹⁰ . In embodiments, R ² is NR ¹¹ C(O)NR ⁸ R ⁹ . In embodiments, R ² is (CH ₂ )rR ¹² . In embodiments, r is 0. In embodiments, r is 1. In embodiments, r is 2. In embodiments, r is 3. In embodiments, r is 4. In embodiments, r is 0 or 1. In embodiments, R ² is halogen (e.g., F, Cl, Br, or I). In embodiments, R ¹ is present. In embodiments, R ² is present. In embodiments, one of R ¹ and R ² is present. In embodiments, one of R ¹ and R ² is present and is Substructure A ( ) or halogen (e.g., F, Cl, Br, or I). In embodiments, one of R ¹ and R ² is present and is Substructure A ( ). In embodiments, two R ¹ or two R ² , together to which the atoms they are attached form a 5- to 10-membered ring (e.g., 5- to 10-membered carbocyclic, heterocyclic, aryl, or heteroaryl ring). In embodiments, o is 0. In embodiments, o is 1. In embodiments, o is 2. In embodiments, o is 1 or 2. In embodiments, o is 0 or 1. In embodiments, o is not 0. In embodiments, R ³ is present. In embodiments, R ³ is OH. In embodiments, R ³ is CN. In embodiments, R ³ is halogen (e.g., F, Cl, Br, or I). In embodiments, R ³ is C _1-6 aliphatic. In embodiments, R ³ is unsubstituted C _1-6 aliphatic. In embodiments, R ³ is substituted C _1-6 aliphatic (e.g., comprising 1, 2, or 3 substituent groups). In embodiments, R ³ is C _1-6 alkoxy. In embodiments, R ³ is unsubstituted C _1-6 alkoxy. In embodiments, R ³ is substituted C _1-6 alkoxy (e.g., comprising 1, 2, or 3 substituent groups). In embodiments, R ³ is NR ⁸ R ⁹ . In embodiments, R ³ is C(O)R ¹⁰ . In embodiments, R ³ is CO ₂ R ¹⁰ . In embodiments, R ³ is C(O)NR ⁸ R ⁹ . In embodiments, R ³ is NR ¹¹ C(O)R ¹⁰ . In embodiments, R ³ is NR ¹¹ CO ₂ R ¹⁰ . In embodiments, R ³ is NR ¹¹ C(O)NR ⁸ R ⁹ . In embodiments, R ³ is (CH ₂ )rR ¹² . In embodiments, r is 0. In embodiments, r is 1. In embodiments, r is 2. In embodiments, r is 3. In embodiments, r is 4. In embodiments, r is 0 or 1. In embodiments, R ³ is methyl, halogen, or CN. In embodiments, R ³ is methyl. In embodiments, R ⁵ is H. In embodiments, R ⁵ is OH. In embodiments, R ⁵ is CN. In embodiments, R ⁵ is halogen (e.g., F, Cl, Br, or I). In embodiments, R ⁵ is C _1-6 aliphatic. In embodiments, R ⁵ is unsubstituted C _1-6 aliphatic. In embodiments, R ⁵ is substituted C _1-6 aliphatic (e.g., comprising 1, 2, or 3 substituent groups). In embodiments, R ⁵ is C _1-6 alkoxy. In embodiments, R ⁵ is unsubstituted C _1-6 alkoxy. In embodiments, R ⁵ is substituted C _1-6 alkoxy (e.g., comprising 1, 2, or 3 substituent groups). In embodiments, R ⁵ is NR ⁸ R ⁹ . In embodiments, R ⁵ is C(O)R ¹⁰ . In embodiments, R ⁵ is CO ₂ R ¹⁰ . In embodiments, R ⁵ is C(O)NR ⁸ R ⁹ . In embodiments, R ⁵ is NR ¹¹ C(O)R ¹⁰ . In embodiments, R ⁵ is NR ¹¹ CO2R ¹⁰ . In embodiments, R ⁵ is NR ¹¹ C(O)NR ⁸ R ⁹ . In embodiments, R ⁵ is (CH ₂ ) _r R ¹² . In embodiments, r is 0. In embodiments, r is 1. In embodiments, r is 2. In embodiments, r is 3. In embodiments, r is 4. In embodiments, r is 0 or 1. In embodiments, R ⁸ is H. In embodiments, R ⁸ is C _1-6 alkyl. In embodiments, a C _1-6 alkyl is unsubstituted. In embodiments, a C _1-6 alkyl is substituted (e.g., comprising 1, 2, or 3 substituent groups). In embodiments, R ⁹ is H. In embodiments, R ⁹ is C _1-6 alkyl. In embodiments, a C _1-6 alkyl is unsubstituted. In embodiments, a C _1-6 alkyl is substituted (e.g., comprising 1, 2, or 3 substituent groups). In embodiments, R ¹¹ is H. In embodiments, R ¹¹ is C _1-6 alkyl. In embodiments, a C _1-6 alkyl is unsubstituted. In embodiments, a C _1-6 alkyl is substituted (e.g., comprising 1, 2, or 3 substituent groups). In embodiments, R ⁸ and R ⁹ , together with the nitrogen atom to which they are attached, form a 3- to 10-membered heterocyclyl. In embodiments, a 3- to 10-membered heterocyclyl is unsubstituted. In embodiments, a 3- to 10-membered heterocyclyl is unsubstituted (e.g., comprising 1, 2, or 3 substituent groups). In embodiments, R ⁸ and R ¹¹ , together with the atoms to which they are attached, form a 3- to 10-membered heterocyclyl. In embodiments, a 3- to 10-membered heterocyclyl is unsubstituted. In embodiments, a 3- to 10-membered heterocyclyl is unsubstituted (e.g., comprising 1, 2, or 3 substituent groups). In embodiments, R ¹⁰ is C _1-6 aliphatic. In embodiments, R ¹⁰ is C ₃ -C ₁₀ cycloaliphatic (e.g., monocyclic or bicyclic cycloaliphatic). In embodiments, R ¹⁰ is 3- to 10-membered heterocyclyl (e.g., monocyclic or bicyclic heterocyclyl). In embodiments, R ¹⁰ is phenyl. In embodiments, R ¹⁰ is naphthyl. In embodiments, R ¹⁰ is 5- to 12-membered heteroaryl (e.g., monocyclic or bicyclic heteroaryl). In embodiments, R ¹⁰ is unsubstituted C _1-6 aliphatic. In embodiments, R ¹⁰ is unsubstituted C ₃ - C ₁₀ cycloaliphatic. In embodiments, R ¹⁰ is unsubstituted 3- to 10-membered heterocyclyl. In embodiments, R ¹⁰ is unsubstituted phenyl. In embodiments, R ¹⁰ is unsubstituted naphthyl. In embodiments, R ¹⁰ is unsubstituted 5- to 12-membered heteroaryl. In embodiments, R ¹⁰ is substituted C _1-6 aliphatic. In embodiments, R ¹⁰ is substituted C ₃ -C ₁₀ cycloaliphatic. In embodiments, R ¹⁰ is substituted 3- to 10-membered heterocyclyl. In embodiments, R ¹⁰ is substituted phenyl. In embodiments, R ¹⁰ is substituted naphthyl. In embodiments, R ¹⁰ is substituted 5- to 12-membered heteroaryl. In embodiments, a substituted group comprises 1, 2, or 3 substituent groups as described herein. In embodiments, R ¹⁰ and R ¹¹ , together with the atoms to which they are attached, form a 3- to 10-membered heterocyclyl. In embodiments, a 3- to 10-membered heterocyclyl is unsubstituted. In embodiments, a 3- to 10-membered heterocyclyl is substituted (e.g., comprising 1, 2, or 3 substituent groups). In embodiments, R ¹² is C ₃ -C ₁₀ cycloaliphatic (e.g., monocyclic or bicyclic cycloaliphatic). In embodiments, R ¹² is 3- to 10-membered heterocyclyl (e.g., monocyclic or bicyclic heterocyclyl). In embodiments, R ¹² is phenyl. In embodiments, R ¹² is naphthyl. In embodiments, R ¹² is 5- to 12-membered heteroaryl (e.g., monocyclic or bicyclic heteroaryl). In embodiments, R ¹² is unsubstituted C ₃ -C ₁₀ cycloaliphatic. In embodiments, R ¹² is unsubstituted 3- to 10-membered heterocyclyl. In embodiments, R ¹² is unsubstituted phenyl. In embodiments, R ¹² is unsubstituted naphthyl. In embodiments, R ¹² is unsubstituted 5- to 12- membered heteroaryl. In embodiments, R ¹² is substituted C ₃ -C ₁₀ cycloaliphatic. In embodiments, R ¹² is substituted 3- to 10-membered heterocyclyl. In embodiments, R ¹² is substituted phenyl. In embodiments, R ¹² is substituted naphthyl. In embodiments, R ¹² is substituted 5- to 12-membered heteroaryl. In embodiments, a substituted group comprises 1, 2, or 3 substituent groups as described herein. [0154] In embodiments, a compound of the invention comprising a Class C ligand has a structure selected from the following formulas selected from Table C1. In embodiments, an E moiety is selected from those described in Table D, where shows the point of covalent attachment to moiety L ^P . In embodiments, -L ^P -E is according to any of substructures (D1)- (D49) as described herein. In embodiments, -L ^P -E is according to any of substructures (D1)’- (D49)’ as described herein. Table C1. Exemplary Formulas Comprising Class C Ligands or a pharmaceutically acceptable salt thereof, wherein R ^4A is a first R ⁴ group, R ^4B is a second R ⁴ group, R ^4C is a third R ⁴ group, R ^4D is a fourth R ⁴ group, preferably R ⁴ is unsubstituted C _1-6 alkyl if one or more of R ^4A , R ^4B , and R ^4C is also present; and p is 0 or 1. [0155] In embodiments, the compound comprises a ligand formed from any one Compounds (1)-(169) of PCT/US22/28755, or a pharmaceutically acceptable salt thereof. [0156] In embodiments, the compound comprises a ligand derived from any one of Compounds (1)-(169) of PCT/US22/28755, or a pharmaceutically acceptable salt thereof. In embodiments, the compound of PCT/US22/28755 is modified to include a piperazine- or piperazine-containing group covalently attached to the -L ^P -E group as described herein. [0157] In embodiments, the compound is selected from any of the following compounds of Table C2 and C3, or a pharmaceutically acceptable salt thereof. In embodiments, an E moiety is selected from those described in Table D, where shows the point of covalent attachment to moiety L ^P . In embodiments, -L ^P -E is according to any of substructures (D1)- (D49) as described herein. Table C2. Exemplary Compounds Comprising Class C Ligands

Table C3. Exemplary Compounds Comprising Class C Ligands

Exemplary L ^P and E Groups [0158] Exemplary linkers (L ^P ) and E3 ubiquitin ligase ligands (E) suitable for inclusion in the compounds of the invention include any known in the art. Exemplary structures for L ^P and/or E include those described in the below, each of which is incorporated by reference in its entirety. [0159] In embodiments, a linker L ^P is a covalent bond. [0160] In embodiments, a linker L ^P comprises a heterocycyl directly attached to the Ligand or attached to Ligand via a methylene (CH ₂ ) moiety. In embodiments, a linker L ^P comprises a substructure F1 or a substructure F2 where * indicates the point of covalent attachment to the Ligand. [0161] In embodiments, a linker L ^P comprises a C ₁ -C ₂₀ alkylene. [0162] In embodiments, a linker L ^P is a C ₁ -C ₂₀ alkylene. [0163] In embodiments, a linker L ^P comprises an unsubstituted C ₁ -C ₂₀ alkylene. In embodiments, a linker L ^P comprises an unsubstituted C ₂ -C ₁₀ alkylene. In embodiments, a linker L ^P comprises an unsubstituted, linear C ₂ -C ₁₀ alkylene. In embodiments, a linker L ^P is comprises unsubstituted C ₃ -C ₁₀ alkylene. [0164] In embodiments, a linker L ^P is an unsubstituted C ₁ -C ₂₀ alkylene. In embodiments, a linker L ^P is an unsubstituted C ₂ -C ₁₀ alkylene. In embodiments, a linker L ^P is an unsubstituted, linear C ₂ -C ₁₀ alkylene. In embodiments, a linker L ^P is an unsubstituted C ₃ -C ₁₀ alkylene. [0165] In embodiments, a linker L ^P comprises a C ₁ -C ₂₀ alkylene comprising an oxo (=O) substituent (e.g., a C ₁ -C ₂₀ alkylene comprising 1, 2, or 3 oxo (=O) substituents as valency permits). [0166] In embodiments, a linker L ^P is a C ₁ -C ₂₀ alkylene comprising an oxo (=O) substituent (e.g., a C ₁ -C ₂₀ alkylene comprising 1, 2, or 3 oxo (=O) substituents as valency permits). [0167] In embodiments, a linker L ^P comprises a C ₂ -C ₂₀ heteroalkylene. [0168] In embodiments, a linker L ^P is a C ₂ -C ₂₀ heteroalkylene. [0169] In embodiments, a linker L ^P comprises an unsubstituted C ₂ -C ₂₀ heteroalkylene. In embodiments, a linker L ^P comprises an unsubstituted C ₂ -C ₁₀ heteroalkylene. In embodiments, a linker L ^P comprises an unsubstituted, linear C ₂ -C ₁₀ heteroalkylene. In embodiments, a linker L ^P comprises an unsubstituted C ₃ -C ₁₀ heteroalkylene. [0170] In embodiments, a linker L ^P is an unsubstituted C ₂ -C ₂₀ heteroalkylene. In embodiments, a linker L ^P is an unsubstituted C ₂ -C ₁₀ heteroalkylene. In embodiments, a linker L ^P is an unsubstituted, linear C ₂ -C ₁₀ heteroalkylene. In embodiments, a linker L ^P is an unsubstituted C ₃ -C ₁₀ heteroalkylene. [0171] In embodiments, a linker L ^P comprises a C ₂ -C ₂₀ heteroalkylene comprising an oxo (=O) substituent (e.g., a C ₂ -C ₂₀ heteroalkylene comprising 1, 2, or 3 oxo (=O) substituents as valency permits). [0172] In embodiments, a linker L ^P is a C ₂ -C ₂₀ heteroalkylene comprising an oxo (=O) substituent (e.g., a C ₂ -C ₂₀ heteroalkylene comprising 1, 2, or 3 oxo (=O) substituents as valency permits). [0173] In embodiments, a linker L ^P comprises a C ₂ -C ₂₀ monoalkynylene. [0174] In embodiments, a linker L ^P is a C ₂ -C ₂₀ monoalkynylene. [0175] In embodiments, a linker L ^P comprises an unsubstituted C ₂ -C ₂₀ monoalkynylene. In embodiments, a linker L ^P comprises an unsubstituted C ₂ -C ₁₀ monoalkynylene. In embodiments, a linker L ^P comprises an unsubstituted, linear C ₂ -C ₁₀ monoalkynylene. In embodiments, a linker L ^P comprises an unsubstituted, branched C ₄ -C ₁₀ monoalkynylene. [0176] In embodiments, a linker L ^P is an unsubstituted C ₂ -C ₂₀ monoalkynylene. In embodiments, a linker L ^P is an unsubstituted C ₂ -C ₁₀ monoalkynylene. In embodiments, a linker L ^P is an unsubstituted, linear C ₂ -C ₁₀ monoalkynylene. In embodiments, a linker L ^P is an unsubstituted, branched C ₄ -C ₁₀ monoalkynylene. [0177] In embodiments, a linker L ^P comprises a C ₃ -C ₂₀ monoalkynylene comprising an oxo (=O) substituent (e.g., a C ₃ -C ₂₀ heteroalkylene comprising 1, 2, or 3 oxo (=O) substituents as valency permits). [0178] In embodiments, a linker L ^P is a C ₃ -C ₂₀ monoalkynylene comprising an oxo (=O) substituent (e.g., a C ₃ -C ₂₀ monoalkynylene comprising 1, 2, or 3 oxo (=O) substituents as valency permits). [0179] In embodiments, a linker L ^P comprises one or more ethyleneglycol moieties. In embodiments, a linker L ^P comprises 1, 2, 3, 4, or 5 ethyleneglycol repeating units. In embodiments, a linker L ^P further comprises an oxo (=O) subsitutent (e.g., comprising 1, 2, or 3 oxo (=O) substituents as valency permits). [0180] In embodiments, a linker L ^P comprises (1) an alkylene moiety (CH ₂ ), (CH ₂ ) ₂ , (CH ₂ ) ₃ , (CH ₂ ) ₄ , (CH ₂ ) ₅ , (CH ₂ ) ₆ , (CH ₂ ) ₇ , (CH ₂ ) ₈ , (CH ₂ ) ₉ , or (CH ₂ ) ₁₀ ; and (2) substructure F1 or substructure F2. [0181] In embodiments, a linker L ^P is (CH ₂ ), (CH ₂ ) ₂ , (CH ₂ ) ₃ , (CH ₂ ) ₄ , (CH ₂ ) ₅ , (CH ₂ ) ₆ , (CH ₂ ) ₇ , (CH ₂ ) ₈ , (CH ₂ ) ₉ , or (CH ₂ ) ₁₀ . [0182] In embodiments, a linker L ^P comprises –O(CH ₂ CH ₂ O) ₂ (CH ₂ ) ₂ -, -O(CH ₂ CH ₂ O)(CH ₂ ) ₂ -, -O(CH ₂ CH ₂ O) ₃ (CH ₂ ) ₂ -, -O(CH ₂ CH ₂ O) ₄ (CH ₂ ) ₂ -, or -O(CH ₂ CH ₂ O) ₅ (CH ₂ ) ₂ -. [0183] In embodiments, a linker L ^P comprises (1) –O(CH ₂ CH ₂ O) ₂ (CH ₂ ) ₂ -, -O(CH ₂ CH ₂ O)(CH ₂ ) ₂ -, -O(CH ₂ CH ₂ O) ₃ (CH ₂ ) ₂ -, -O(CH ₂ CH ₂ O) ₄ (CH ₂ ) ₂ -, or -O(CH ₂ CH ₂ O) ₅ (CH ₂ ) ₂ -; and (2) substructure F1 or substructure F2. [0184] In embodiments, a linker L ^P is –O(CH ₂ CH ₂ O) ₂ (CH ₂ ) ₂ -, -O(CH ₂ CH ₂ O)(CH ₂ ) ₂ -, -O(CH ₂ CH ₂ O) ₃ (CH ₂ ) ₂ -, -O(CH ₂ CH ₂ O) ₄ (CH ₂ ) ₂ -, or -O(CH ₂ CH ₂ O) ₅ (CH ₂ ) ₂ -. [0185] In embodiments, a linker L ^P comprises –O(CH ₂ CH ₂ O)CH ₂ C(O)-, –O(CH ₂ CH ₂ O) ₂ CH ₂ C(O)-, –O(CH ₂ CH ₂ O) ₃ CH ₂ C(O)-, –O(CH ₂ CH ₂ O) ₄ CH ₂ C(O)-, or – O(CH ₂ CH ₂ O) ₅ CH ₂ C(O)-. [0186] In embodiments, a linker L ^P comprises: (1) –O(CH ₂ CH ₂ O)CH ₂ C(O)-, –O(CH ₂ CH ₂ O) ₂ CH ₂ C(O)-, –O(CH ₂ CH ₂ O) ₃ CH ₂ C(O)-, –O(CH ₂ CH ₂ O) ₄ CH ₂ C(O)-, or – O(CH ₂ CH ₂ O) ₅ CH ₂ C(O)-; and (2) substructure F1 or substructure F2. [0187] In embodiments, a linker L ^P is –O(CH ₂ CH ₂ O)CH ₂ C(O)-, –O(CH ₂ CH ₂ O) ₂ CH ₂ C(O)-, –O(CH ₂ CH ₂ O) ₃ CH ₂ C(O)-, –O(CH ₂ CH ₂ O) ₄ CH ₂ C(O)-, or – O(CH ₂ CH ₂ O) ₅ CH ₂ C(O)-. [0188] In embodiments, a linker L ^P comprises -NHC(O)CH ₂ O(CH ₂ CH ₂ O)(CH ₂ ) ₂ -, -NHC(O)CH ₂ O(CH ₂ CH ₂ O) ₂ (CH ₂ ) ₂ -, -NHC(O)CH ₂ O(CH ₂ CH ₂ O) ₃ (CH ₂ ) ₂ -, -NHC(O)CH ₂ O(CH ₂ CH ₂ O) ₄ (CH ₂ ) ₂ -, or -NHC(O)CH ₂ O(CH ₂ CH ₂ O) ₅ (CH ₂ ) ₂ -. [0189] In embodiments, a linker L ^P comprises: (1) -NHC(O)CH ₂ O(CH ₂ CH ₂ O)(CH ₂ ) ₂ -, -NHC(O)CH ₂ O(CH ₂ CH ₂ O) ₂ (CH ₂ ) ₂ -, -NHC(O)CH ₂ O(CH ₂ CH ₂ O) ₃ (CH ₂ ) ₂ -, -NHC(O)CH ₂ O(CH ₂ CH ₂ O) ₄ (CH ₂ ) ₂ -, or -NHC(O)CH ₂ O(CH ₂ CH ₂ O) ₅ (CH ₂ ) ₂ -; and (2) substructure F1 or substructure F2. [0190] In embodiments, a linker L ^P is -NHC(O)CH ₂ O(CH ₂ CH ₂ O)(CH ₂ ) ₂ -, -NHC(O)CH ₂ O(CH ₂ CH ₂ O) ₂ (CH ₂ ) ₂ -, -NHC(O)CH ₂ O(CH ₂ CH ₂ O) ₃ (CH ₂ ) ₂ -, -NHC(O)CH ₂ O(CH ₂ CH ₂ O) ₄ (CH ₂ ) ₂ -, or -NHC(O)CH ₂ O(CH ₂ CH ₂ O) ₅ (CH ₂ ) ₂ -. [0191] In embodiments, a linker L ^P comprises -NHC(O)CH ₂ O(CH ₂ CH ₂ O)(CH ₂ ) ₂ C(O)-, -NHC(O)CH ₂ O(CH ₂ CH ₂ O) ₂ (CH ₂ ) ₂ C(O)-, -NHC(O) CH ₂ O(CH ₂ CH ₂ O) ₃ (CH ₂ ) ₂ C(O)-, -NHC(O)CH ₂ O(CH ₂ CH ₂ O) ₄ (CH ₂ ) ₂ C(O)-, or -NHC(O)CH ₂ O(CH ₂ CH ₂ O) ₅ (CH ₂ ) ₂ C(O)-. [0192] In embodiments, a linker L ^P comprises (1) -NHC(O)CH ₂ O(CH ₂ CH ₂ O)(CH ₂ ) ₂ C(O)-, -NHC(O)CH ₂ O(CH ₂ CH ₂ O) ₂ (CH ₂ ) ₂ C(O)-, -NHC(O) CH ₂ O(CH ₂ CH ₂ O) ₃ (CH ₂ ) ₂ C(O)-, -NHC(O)CH ₂ O(CH ₂ CH ₂ O) ₄ (CH ₂ ) ₂ C(O)-, or -NHC(O)CH ₂ O(CH ₂ CH ₂ O) ₅ (CH ₂ ) ₂ C(O)-; and (2) substructure F1 or substructure F2. [0193] In embodiments, a linker L ^P is: -NHC(O)CH ₂ O(CH ₂ CH ₂ O)(CH ₂ ) ₂ C(O)-, -NHC(O)CH ₂ O(CH ₂ CH ₂ O) ₂ (CH ₂ ) ₂ C(O)-, -NHC(O) CH ₂ O(CH ₂ CH ₂ O) ₃ (CH ₂ ) ₂ C(O)-, -NHC(O)CH ₂ O(CH ₂ CH ₂ O) ₄ (CH ₂ ) ₂ C(O)-, or -NHC(O)CH ₂ O(CH ₂ CH ₂ O) ₅ (CH ₂ ) ₂ C(O)-. [0194] In embodiments, a linker L ^P comprises –NH(CH ₂ )C(O)-, -NH(CH ₂ ) ₂ C(O)-, -NH(CH ₂ ) ₃ C(O)-, -NH(CH ₂ ) ₄ C(O)-, or -NH(CH ₂ ) ₅ C(O)-. [0195] In embodiments, a linker L ^P comprises: (1) –NH(CH ₂ )C(O)-, -NH(CH ₂ ) ₂ C(O)-, -NH(CH ₂ ) ₃ C(O)-, -NH(CH ₂ ) ₄ C(O)-, or -NH(CH ₂ ) ₅ C(O)-; and (2) substructure F1 or substructure F2. [0196] In embodiments, a linker L ^P is –NH(CH ₂ )C(O)-, -NH(CH ₂ ) ₂ C(O)-, -NH(CH ₂ ) ₃ C(O)-, -NH(CH ₂ ) ₄ C(O)-, or -NH(CH ₂ ) ₅ C(O)-. [0197] In embodiments, a linker L ^P comprises -(NHCH ₂ C(O)NH)(CH ₂ )(NHCH ₂ C(O)-, -(NHCH ₂ C(O)NH)(CH ₂ ) ₂ (NHCH ₂ C(O)-, - (NHCH ₂ C(O)NH)(CH ₂ ) ₃ (NHCH ₂ C(O)-, -(NHCH ₂ C(O)NH)(CH ₂ ) ₄ (NHCH ₂ C(O)-, or -(NHCH ₂ C(O)NH)(CH ₂ ) ₅ (NHCH ₂ C(O)-. [0198] In embodiments, a linker L ^P comprises: (1) -(NHCH ₂ C(O)NH)(CH ₂ )(NHCH ₂ C(O)-, -(NHCH ₂ C(O)NH)(CH ₂ ) ₂ (NHCH ₂ C(O)-, -(NHC H ₂ C(O)NH)(CH ₂ ) ₃ (NHCH ₂ C(O)-, -(NHCH ₂ C(O)NH)(CH ₂ ) ₄ (NHCH ₂ C(O)-, or -(NHCH ₂ C(O)NH)(CH ₂ ) ₅ (NHCH ₂ C(O)-; and (2) substructure F1 or substructure F2. [0199] In embodiments, a linker L ^P is -(NHCH ₂ C(O)NH)(CH ₂ )(NHCH ₂ C(O)-, -(NHCH ₂ C(O)NH)(CH ₂ ) ₂ (NHCH ₂ C(O)-, -(NHCH ₂ C(O)NH)(CH ₂ ) ₃ (NHCH ₂ C(O)-, -(NHCH ₂ C(O)NH)(CH ₂ ) ₄ (NHCH ₂ C(O)-, or -(NHCH ₂ C(O)NH)(CH ₂ ) ₅ (NHCH ₂ C(O)-. [0200] In embodiments, a linker L ^P comprises –NH(CH ₂ )C(O)-, -NH(CH ₂ ) ₂ C(O)-, -NH(CH ₂ ) ₃ C(O)-, -NH(CH ₂ ) ₄ C(O)-, or -NH(CH ₂ ) ₅ C(O)-. [0201] In embodiments, a linker L ^P comprises: (1) –NH(CH ₂ )C(O)-, -NH(CH ₂ ) ₂ C(O)-, -NH(CH ₂ ) ₃ C(O)-, -NH(CH ₂ ) ₄ C(O)-, or -NH(CH ₂ ) ₅ C(O)-; and (2) substructure F1 or substructure F2. [0202] In embodiments, a linker L ^P is –NH(CH ₂ )C(O)-, -NH(CH ₂ ) ₂ C(O)-, -NH(CH ₂ ) ₃ C(O)-, -NH(CH ₂ ) ₄ C(O)-, or -NH(CH ₂ ) ₅ C(O)-. [0203] In embodiments, a linker L ^P comprises -NHC(O)CH ₂ O(CH ₂ ) ₂ C(O)-, -NHC(O)CH ₂ O(CH ₂ ) ₃ C(O)-, -NHC(O)CH ₂ O(CH ₂ ) ₄ C (O)-, -NHC(O)CH ₂ O(CH ₂ ) ₅ C(O)-, or -NHC(O)CH ₂ O(CH ₂ ) ₆ C(O)-. [0204] In embodiments, a linker L ^P comprises: (1) -NHC(O)CH ₂ O(CH ₂ ) ₂ C(O)-, -NHC(O)CH ₂ O(CH ₂ ) ₃ C(O)-, -NHC(O)CH ₂ O(CH ₂ ) ₄ C(O)-, - NHC(O)CH ₂ O(CH ₂ ) ₅ C(O)-, or -NHC(O)CH ₂ O(CH ₂ ) ₆ C(O)-; and (2) substructure F1 or substructure F2. [0205] In embodiments, a linker L ^P is -NHC(O)CH ₂ O(CH ₂ ) ₂ C(O)-, -NHC(O)CH ₂ O(CH ₂ ) ₃ C(O)-, -NHC(O)CH ₂ O(CH ₂ ) ₄ C(O)-, -N HC(O)CH ₂ O(CH ₂ ) ₅ C(O)-, or -NHC(O)CH ₂ O(CH ₂ ) ₆ C(O)-. [0206] In embodiments, a linker L ^P comprises -≡-(CH ₂ )-, -≡-(CH ₂ ) ₂ -, -≡-(CH ₂ ) ₃ -, -≡-(CH ₂ ) ₄ -, -≡-(CH ₂ ) ₅ -, -≡-(CH ₂ ) ₆ , -≡-(CH ₂ ) ₇ , or -≡-(CH ₂ ) ₈ . [0207] In embodiments, a linker L ^P comprises: (1) -≡-(CH ₂ )-, -≡-(CH ₂ ) ₂ -, -≡-(CH ₂ ) ₃ -, -≡-(CH ₂ ) ₄ -, -≡-(CH ₂ ) ₅ -, -≡-(CH ₂ ) ₆ , -≡-(CH ₂ ) ₇ , or -≡-(CH ₂ ) ₈ ; and (2) substructure F1 or substructure F2. [0208] In embodiments, a linker L ^P is -≡-(CH ₂ )-, -≡-(CH ₂ ) ₂ -, -≡-(CH ₂ ) ₃ -, -≡-(CH ₂ ) ₄ -, -≡-(CH ₂ ) ₅ -, -≡-(CH ₂ ) ₆ , -≡-(CH ₂ ) ₇ , or -≡-(CH ₂ ) ₈ . [0209] In embodiments, a linker L ^P comprises -≡-(CH ₂ )OCH ₂ CH ₂ OCH ₂ C(O)-, -≡-(CH ₂ )NHCH ₂ CH ₂ NHCH ₂ C(O)-, or -≡-(CH ₂ )OCH ₂ CH ₂ NHC(O)CH ₂ -. [0210] In embodiments, a linker L ^P comprises: (1) -≡-(CH ₂ )OCH ₂ CH ₂ OCH ₂ C(O)-, -≡-(CH ₂ )NHCH ₂ CH ₂ NHCH ₂ C(O)-, or -≡-(CH ₂ )OCH ₂ CH ₂ NHC(O)CH ₂ -; and (2) substructure F1 or substructure F2. [0211] In embodiments, a linker L ^P is -≡-(CH ₂ )OCH ₂ CH ₂ OCH ₂ C(O)-, -≡-(CH ₂ )NHCH ₂ CH ₂ NHCH ₂ C(O)-, or -≡-(CH ₂ )OCH ₂ CH ₂ NHC(O)CH ₂ -. [0212] In embodiments, an E moiety is selected from those described in Table D, where shows the point of covalent attachment to moiety L ^P . Table D. Exemplary E Moieties

[0213] In embodiments, an L ^P -E moiety is selected from those described in Table E1. Table E1. Exemplary L ^P -E Moieties

[0214] In embodiments, an L ^P -E moiety is selected from those described in Table E2. Table E2. Exemplary L ^P -E Moieties

[0215] In embodiments, an L ^P -E moiety is selected from those described in Table E3. Table E3. Exemplary L ^P -E Moieties

Additional Exemplary LP-E Moieties [0216] In certain embodiments, an L ^P -E moiety comprises, corresponds to, or is derived from that present in ARV-110, ARV-471, AC682, ARV-766, CC-94676, DT2216, FHD-609, KT- 474, KT-413, KT-333, NX-2127, NX-5948, CFT8634, CFT8919, or CG001419, including any fragments thereof. In certain embodiments, an L ^P -E moiety comprises, corresponds to, or is derived from that present in BGB-16673, HK29116, LNK-01002, AC682, HP618, or GT- 20029, including fragments thereof. Exemplary Group 1 [0217] In certain embodiments, L ^P -E moieties include any of those described in WO2021121261, which is incorporated herein by reference in its entirety, as well any moieties corresponding to L ^P and/or E described therein. In embodiments, -L ^P -E comprises, corresponds to, or is derived from a moiety described at pages 28-30 of WO2021121261. [0218] In certain embodiments, L ^P -E moieties include any of those described in US20190106417, which is incorporated herein by reference in its entirety, as well any moieties corresponding to L ^P and/or E described therein. In embodiments, -L ^P -E comprises, corresponds to, or is derived from a moiety described therein, including any fragments thereof. [0219] In certain embodiments, L ^P -E moieties include any of those described in WO2018119441, which is incorporated herein by reference in its entirety, as well any moieties corresponding to L ^P and/or E described therein. In embodiments, -L ^P -E comprises, corresponds to, or is derived from a moiety described therein, including any fragments thereof. [0220] In certain embodiments, L ^P -E moieties include any of the PROTAC degraders described in WO2022047145A1, which is incorporated herein by reference in its entirety, as well any moieties corresponding to L ^P and/or E described therein. In embodiments, -L ^P -E comprises, corresponds to, or is derived from a moiety described therein, including any fragments thereof. [0221] In certain embodiments, L ^P -E moieties include any of the PROTAC degraders described in US20220259154A1, which is incorporated herein by reference in its entirety, as well any moieties corresponding to L ^P and/or E described therein. In embodiments, -L ^P -E comprises, corresponds to, or is derived from a moiety described therein, including any fragments thereof. [0222] In certain embodiments, L ^P -E moieties include any of the PROTAC degraders described in US20220162163A1, which is incorporated herein by reference in its entirety, as well any moieties corresponding to L ^P and/or E described therein. In embodiments, -L ^P -E comprises, corresponds to, or is derived from a moiety described therein, including any fragments thereof. [0223] In certain embodiments, L ^P -E moieties include any of the PROTAC degraders described in US20220144809A1, which is incorporated herein by reference in its entirety, as well any moieties corresponding to L ^P and/or E described therein. In embodiments, -L ^P -E comprises, corresponds to, or is derived from a moiety described therein, including any fragments thereof. [0224] In certain embodiments, L ^P -E moieties include any of the PROTAC degraders described in US20220127279A1, which is incorporated herein by reference in its entirety, as well any moieties corresponding to L ^P and/or E described therein. In embodiments, -L ^P -E comprises, corresponds to, or is derived from a moiety described therein, including any fragments thereof. [0225] In certain embodiments, L ^P -E moieties include any of the PROTAC degraders described in US20220089570A1, which is incorporated herein by reference in its entirety, as well any moieties corresponding to L ^P and/or E described therein. In embodiments, -L ^P -E comprises, corresponds to, or is derived from a moiety described therein, including any fragments thereof. [0226] In certain embodiments, L ^P -E moieties include any of the PROTAC degraders described in US20210187108A1, which is incorporated herein by reference in its entirety, as well any moieties corresponding to L ^P and/or E described therein. In embodiments, -L ^P -E comprises, corresponds to, or is derived from a moiety described therein, including any fragments thereof. [0227] In certain embodiments, L ^P -E moieties include any of the PROTAC degraders described in US20210145832A1, which is incorporated herein by reference in its entirety, as well any moieties corresponding to L ^P and/or E described therein. In embodiments, -L ^P -E comprises, corresponds to, or is derived from a moiety described therein, including any fragments thereof. [0228] In certain embodiments, L ^P -E moieties include any of the PROTAC degraders described in US20210040081A1, which is incorporated herein by reference in its entirety, as well any moieties corresponding to L ^P and/or E described therein. In embodiments, -L ^P -E comprises, corresponds to, or is derived from a moiety described therein, including any fragments thereof. [0229] In certain embodiments, L ^P -E moieties include any of the PROTAC degraders described in US20200392131A1, which is incorporated herein by reference in its entirety, as well any moieties corresponding to L ^P and/or E described therein. In embodiments, -L ^P -E comprises, corresponds to, or is derived from a moiety described therein, including any fragments thereof. [0230] In certain embodiments, L ^P -E moieties include any of the PROTAC degraders described in US20200155690A1, which is incorporated herein by reference in its entirety, as well any moieties corresponding to L ^P and/or E described therein. In embodiments, -L ^P -E comprises, corresponds to, or is derived from a moiety described therein, including any fragments thereof. [0231] In certain embodiments, L ^P -E moieties include any of the PROTAC degraders described in US20180346461A1, which is incorporated herein by reference in its entirety, as well any moieties corresponding to L ^P and/or E described therein. In embodiments, -L ^P -E comprises, corresponds to, or is derived from a moiety described therein, including any fragments thereof. [0232] In certain embodiments, L ^P -E moieties include any of the PROTAC degraders described in US20180237418A1, which is incorporated herein by reference in its entirety, as well any moieties corresponding to L ^P and/or E described therein. In embodiments, -L ^P -E comprises, corresponds to, or is derived from a moiety described therein, including any fragments thereof. [0233] In certain embodiments, L ^P -E moieties include any of the PROTAC degraders described in US20180193470, which is incorporated herein by reference in its entirety, as well any moieties corresponding to L ^P and/or E described therein. In embodiments, -L ^P -E comprises, corresponds to, or is derived from a moiety described therein, including any fragments thereof. [0234] In certain embodiments, L ^P -E moieties include any of the PROTAC degraders described in US20180155322A1, which is incorporated herein by reference in its entirety, as well any moieties corresponding to L ^P and/or E described therein. In embodiments, -L ^P -E comprises, corresponds to, or is derived from a moiety described therein, including any fragments thereof. [0235] In certain embodiments, L ^P -E moieties include any of the PROTAC degraders described in US20180147202A1, which is incorporated herein by reference in its entirety, as well any moieties corresponding to L ^P and/or E described therein. In embodiments, -L ^P -E comprises, corresponds to, or is derived from a moiety described therein, including any fragments thereof. [0236] In certain embodiments, L ^P -E moieties include any of the PROTAC degraders described in US20180072711A1, which is incorporated herein by reference in its entirety, as well any moieties corresponding to L ^P and/or E described therein. In embodiments, -L ^P -E comprises, corresponds to, or is derived from a moiety described therein, including any fragments thereof. [0237] In certain embodiments, L ^P -E moieties include any of the PROTAC degraders described in US20170327469A1, which is incorporated herein by reference in its entirety, as well any moieties corresponding to L ^P and/or E described therein. In embodiments, -L ^P -E comprises, corresponds to, or is derived from a moiety described therein, including any fragments thereof. [0238] In certain embodiments, L ^P -E moieties include any of the PROTAC degraders described in US20160272639A1, which is incorporated herein by reference in its entirety, as well any moieties corresponding to L ^P and/or E described therein. In embodiments, -L ^P -E comprises, corresponds to, or is derived from a moiety described therein, including any fragments thereof. [0239] In certain embodiments, L ^P -E moieties include any of the PROTAC degraders described in US20160214972A1, which is incorporated herein by reference in its entirety, as well any moieties corresponding to L ^P and/or E described therein. In embodiments, -L ^P -E comprises, corresponds to, or is derived from a moiety described therein, including any fragments thereof. [0240] In certain embodiments, L ^P -E moieties include any of the PROTAC degraders described in US20160058872A1, which is incorporated herein by reference in its entirety, as well any moieties corresponding to L ^P and/or E described therein. In embodiments, -L ^P -E comprises, corresponds to, or is derived from a moiety described therein, including any fragments thereof. [0241] In certain embodiments, L ^P -E moieties include any of the PROTAC degraders described in US20160045607A1, which is incorporated herein by reference in its entirety, as well any moieties corresponding to L ^P and/or E described therein. In embodiments, -L ^P -E comprises, corresponds to, or is derived from a moiety described therein, including any fragments thereof. [0242] In certain embodiments, L ^P -E moieties include any of the PROTAC degraders described in US20210220475A1, which is incorporated herein by reference in its entirety, as well any moieties corresponding to L ^P and/or E described therein. In embodiments, E comprises, corresponds to, or is derived from a moiety described therein, including any fragments thereof. [0243] In certain embodiments, L ^P -E moieties include any of the PROTAC degraders described in US20180193470A1, which is incorporated herein by reference in its entirety, as well any moieties corresponding to L ^P and/or E described therein. In embodiments, E comprises, corresponds to, or is derived from a moiety described therein (e.g., those described at paragraphs [0654]-[0953] of US20180193470A1such as Formulas (a)-(f): wherein: W of Formulas (a) through (e) is independently selected from the group CH ₂ , CHR, C═O, SO ₂ , NH, and N-alkyl; X of Formulas (a) through (e) is independently selected from the group O, S and H2; Y of Formulas (a) through (e) is independently selected from the group CH ₂ , —C═CR′, NH, N-alkyl, N-aryl, N-hetaryl, N-cycloalkyl, N-heterocyclyl, O, and S; Z of Formulas (a) through (e) is independently selected from the group O, and S or H2 except that both X and Z cannot be H2; G and G′ of Formulas (a) through (e) are independently selected from the group H, alkyl (linear, branched, optionally substituted), OH, R′OCOOR, R′OCONRR″, CH ₂ -heterocyclyl optionally substituted with R′, and benzyl optionally substituted with R′; Q1-Q4 of Formulas (a) through (e) represent a carbon C substituted with a group independently selected from R′, N or N-oxide; A of Formulas (a) through (e) is independently selected from the group H, alkyl (linear, branched, optionally substituted), cycloalkyl, Cl and F; R of Formulas (a) through (e) comprises, but is not limited to: —CONR′R″, — OR′, —NR′R″, —SR′, —SO2R′, —SO2NR′R″, —CR′R″—, —CR′NR′R″—, —aryl, —hetaryl, —alkyl, —cycloalkyl, —heterocyclyl, —P(O)(OR′)R″, —P(O)R′R″, — OP(O)(OR′)R″, —OP(O)R′R″, —Cl, —F, —Br, —I, —CF3, —CN, — NR′SO2NR′R″, —NR′CONR′R″, —CONR′COR″, —NR′C(═N—CN)NR′R″, — C(═N—CN)NR′R″, —NR′C(═N—CN)R″, —NR′C(═C—NO2)NR′R″, — SO2NR′COR″, —NO2, —CO2R′, —C(C═N—OR′)R″, —CR′═CR′R″, —CCR′, — S(C═O)(C═N—R′)R″, —SF5 and —OCF3 R′ and R″ of Formulas (a) through (e) are independently selected from a bond, H, alkyl, cycloalkyl, aryl, heteroaryl, heterocyclic, —C(═O)R, heterocyclyl, each of which is optionally substituted; n of Formulas (a) through (e) is an integer from 1-10; of Formulas (a) through (e) represents a bond that may be stereospecific ((R) or (S)) or non-stereospecific; and Rn of Formulas (a) through (e) comprises 1-4 independent functional groups or atoms, for example, O, N or S, and optionally, one of which is modified to be covalently joined to a PTM, a chemical linker group (L), a ULM, CLM (or CLM′) or combination thereof. [0244] In embodiments, L ^P comprises, corresponds to, or is derived from a moiety described therein (e.g., those described at paragraphs [0954]-[0993] of US20180193470A1, include those described at paragraphs [0969]-[0977], particularly those described at paragraphs [0975]-[0977]). For example, a linker L ^P may be described by: one or more covalently connected structural units (e.g., —A ^L 1... (A ^L ) _q - or -(A ^L ) _q -), wherein A1 is a group coupled to the ligand moiety, and (A ^L ) _q is a group coupled to the E moiety. [0245] In certain embodiments, the linker group L is selected from -(A ^L ) _q -, wherein (A ^L ) _q is a group which is connected to at least one of a ULM, a PTM moiety, or a combination thereof; q of the linker is an integer greater than or equal to 1; each A ^L q is independently selected from the group consisting of, a bond, CR ^L1 R ^L2 , O, S, SO, SO ₂ , NR ^L3 , SO ₂ NR ^L3 , SONR ^L3 , CONR ^L3 , NR ^L3 CONR ^L4 , NR ^L3 SO ₂ NR ^L4 , CO, CR ^L1 ═CR ^L2 , C≡C, SiR ^L1 R ^L2 , P(O)R ^L1 , P(O)OR ^L1 , NR ^L3 C(═NCN)NR ^L4 , NR ^L3 C(═NCN), NR ^L3 C(═CNO ₂ )NR ^L4 , C _3-11 cycloalkyl optionally substituted with 0-6 R ^L1 and/or R ^L2 groups, C _5-13 spirocycloalkyl optionally substituted with 0-9 R ^L1 and/or R ^L2 groups, C _3-11 heterocyclyl optionally substituted with 0-6 R ^L1 and/or R ^L2 groups, C _5-13 spiroheterocycloalkyl optionally substituted with 0-8 R ^L1 and/or R ^L2 groups, aryl optionally substituted with 0-6 R ^L1 and/or R ^L2 groups, heteroaryl optionally substituted with 0-6 R ^L1 and/or R ^L2 groups, where R ^L1 or R ^L2 , each independently are optionally linked to other groups to form cycloalkyl and/or heterocyclyl moiety, optionally substituted with 0-4 R ^L5 groups; and R ^L1 , R ^L2 , R ^L3 , R ^L and R ^L5 are, each independently, H, halo, C _1-8 alkyl, OC _{1- 8} alkyl, SC _1-8 alkyl, NHC _1-8 alkyl, N(C _1-8 alkyl) ₂ , C _3-11 cycloalkyl, aryl, heteroaryl, C _{3- 11} heterocyclyl, OC _1-8 cycloalkyl, SC _1-8 cycloalkyl, NHC _1-8 cycloalkyl, N(C _{1- 8} cycloalkyl) ₂ , N(C _1-8 cycloalkyl)(C _1-8 alkyl), OH, NH ₂ , SH, SO ₂ C _1-8 alkyl, P(O)(OC _{1- 8} alkyl)(C _1-8 alkyl), P(O)(OC _1-8 alkyl) ₂ , CC—C _1-8 alkyl, CCH, CH═CH(C _1-8 alkyl), C(C _{1- 8} alkyl)═CH(C _1-8 alkyl), C(C _1-8 alkyl)═C(C _1-8 alkyl) ₂ , Si(OH) ₃ , Si(C _1-8 alkyl) ₃ , Si(OH)(C _{1- 8} alkyl) ₂ , COC _1-8 alkyl, CO ₂ H, halogen, CN, CF ₃ , CHF ₂ , CH ₂ F, NO ₂ , SF ₅ , SO ₂ NHC _{1- 8} alkyl, SO ₂ N(C _1-8 alkyl) ₂ , SONHC _1-8 alkyl, SON(C _1-8 alkyl) ₂ , CONHC _1-8 alkyl, CON(C _{1- 8} alkyl) ₂ , N(C _1-8 alkyl)CONH(C _1-8 alkyl), N(C _1-8 alkyl)CON(C _1-8 alkyl) ₂ , NHCONH(C _{1- 8} alkyl), NHCON(C _1-8 alkyl) ₂ , NHCONH ₂ , N(C _1-8 alkyl)SO ₂ NH(C _1-8 alkyl), N(C _1-8 alkyl) SO ₂ N(C _1-8 alkyl) ₂ , NH SO ₂ NH(C _1-8 alkyl), NH SO ₂ N(C _1-8 alkyl) ₂ , NH SO ₂ NH ₂ . [0246] In certain embodiments, q of the linker is an integer greater than or equal to 0. In certain embodiments, q is an integer greater than or equal to 1. [0247] In certain embodiments, e.g., where q of the linker is greater than 2, (A ^L ) _q is a group which is connected to ULM, and A ^L 1 and (A ^L ) _q are connected via structural units of the linker (L). [0248] In certain embodiments, e.g., where q of the linker is 2, (A ^L ) _q is a group which is connected to A ^L ₁ and to a ULM. [0249] In certain embodiments, e.g., where q of the linker is 1, the structure of the linker group L is -A ^L ₁ -, and A ^L ₁ is a group which is connected to a ULM moiety and a PTM moiety. [0250] In certain embodiments, the linker (L) comprises a group represented by a general structure selected from the group consisting of: —NR(CH ₂ ) _n -(lower alkyl)-, —NR(CH ₂ ) _n -(lower alkoxyl)-, —NR(CH ₂ ) _n - (lower alkoxyl)-OCH ₂ —, —NR(CH ₂ ) _n -(lower alkoxyl)-(lower alkyl)-OCH ₂ —, — NR(CH ₂ ) _n -(cycloalkyl)-(lower alkyl)-OCH ₂ -, —NR(CH ₂ ) _n -(hetero cycloalkyl)-, — NR(CH ₂ CH ₂ O) _n -(lower alkyl)-O—CH ₂ —, NR(CH ₂ CH ₂ O) _n -(hetero cycloalkyl)-O— CH ₂ —, —NR(CH ₂ CH ₂ O) _n —Aryl-O—CH ₂ —, —NR(CH ₂ CH ₂ O) _n -(hetero aryl)-O— CH ₂ —, —NR(CH ₂ CH ₂ O) _n -(cyclo alkyl)-O-(hetero aryl)-O—CH ₂ —, — NR(CH ₂ CH ₂ O) _n -(cyclo alkyl)-O-Aryl-O—CH ₂ —, —NR(CH ₂ CH ₂ O) _n -(lower alkyl)- NH-Aryl-O—CH ₂ —, NR(CH ₂ CH ₂ O) _n -(lower alkyl)-O-Aryl-CH ₂ , —NR(CH ₂ CH ₂ O) _n - cycloalkyl-O-Aryl-, NR(CH ₂ CH ₂ O) _n -cycloalkyl-O-(hetero aryl)l-, —NR(CH ₂ CH ₂ ) _n - (cycloalkyl)-O-(heterocycle)-CH ₂ , —NR(CH ₂ CH ₂ ) _n -(heterocycle)-(heterocycle)-CH ₂ , —N(R1R2)-(heterocycle)-CH ₂ ; where n of the linker can be 0 to 10; R of the linker can be H, lower alkyl; R ¹ and R ² of the linker can form a ring with the connecting N. [0251] In certain embodiments, an L ^P -E moiety comprises, corresponds to, or is derived from that present in ARV-471, including any fragments thereof. In embodiments, an L ^P -E moiety has a structure according to (D46), (D46)’, or (D46)”.

[0252] In certain embodiments, an L ^P -E moiety comprises, corresponds to, or is derived from that present in ARV-110, including any fragments thereof. In embodiments, an L ^P -E moiety has a structure according to (D47), (D47)’, or (D47)”. [0253] In certain embodiments, an L ^P -E moiety comprises, corresponds to, or is derived from that present in ARV-771 or ARV-766, including any fragments thereof. Exemplary Group 2 [0254] In certain embodiments, L ^P -E moieties include any of the PROTAC degraders described in US20220274993A1, which is incorporated herein by reference in its entirety, as well any moieties corresponding to L ^P and/or E described therein. In embodiments, -L ^P -E comprises, corresponds to, or is derived from a moiety described therein, including any fragments thereof. [0255] In certain embodiments, L ^P -E moieties include any of the PROTAC degraders described in US20220054453A1, which is incorporated herein by reference in its entirety, as well any moieties corresponding to L ^P and/or E described therein. In embodiments, -L ^P -E comprises, corresponds to, or is derived from a moiety described therein, including any fragments thereof. [0256] In certain embodiments, L ^P -E moieties include any of the PROTAC degraders described in US20210395273A1, which is incorporated herein by reference in its entirety, as well any moieties corresponding to L ^P and/or E described therein. In embodiments, -L ^P -E comprises, corresponds to, or is derived from a moiety described therein, including any fragments thereof. [0257] In certain embodiments, L ^P -E moieties include any of the PROTAC degraders described in US20210228562A1, which is incorporated herein by reference in its entirety, as well any moieties corresponding to L ^P and/or E described therein. In embodiments, -L ^P -E comprises, corresponds to, or is derived from a moiety described therein, including any fragments thereof. [0258] In certain embodiments, L ^P -E moieties include any of the PROTAC degraders described in US20220281831A1, which is incorporated herein by reference in its entirety, as well any moieties corresponding to L ^P and/or E described therein. In embodiments, -L ^P -E comprises, corresponds to, or is derived from a moiety described therein, including any fragments thereof. [0259] In certain embodiments, L ^P -E moieties include any of the PROTAC degraders described in US20210002296A1, which is incorporated herein by reference in its entirety, as well any moieties corresponding to L ^P and/or E described therein. In embodiments, -L ^P -E comprises, corresponds to, or is derived from a moiety described therein, including any fragments thereof. [0260] In certain embodiments, L ^P -E moieties include any of the PROTAC degraders described in US11318205B1, which is incorporated herein by reference in its entirety, as well any moieties corresponding to L ^P and/or E described therein. In embodiments, -L ^P -E comprises, corresponds to, or is derived from a moiety described therein, including any fragments thereof. [0261] In certain embodiments, L ^P -E moieties include any of the PROTAC degraders described in US11117889B1, which is incorporated herein by reference in its entirety, as well any moieties corresponding to L ^P and/or E described therein. In embodiments, -L ^P -E comprises, corresponds to, or is derived from a moiety described therein, including any fragments thereof. [0262] In certain embodiments, L ^P -E moieties include any of the PROTAC degraders described in US20200010468A1, which is incorporated herein by reference in its entirety, as well any moieties corresponding to L ^P and/or E described therein. In embodiments, -L ^P -E comprises, corresponds to, or is derived from a moiety described therein, including any fragments thereof. [0263] In certain embodiments, L ^P -E moieties include any of the PROTAC degraders described in WO2022178532A1, which is incorporated herein by reference in its entirety, as well any moieties corresponding to L ^P and/or E described therein. In embodiments, -L ^P -E comprises, corresponds to, or is derived from a moiety described therein, including any fragments thereof. In embodiments, -L ^P -E comprises, corresponds to, or is derived from a moiety having the following structure: , wherein L is a covalent bond or a bivalent, saturated or partially unsaturated, straight or branched C1-50 hydrocarbon chain, wherein 0-6 methylene units of L are independently replaced by –Cy-, -O-, -N(R)-, –Si(R) ₂ –, –Si(OH)(R)–, –Si(OH) ₂ –, –P(O)(OR)–, –P(O)(R)–, – P(O)(NR2)–, -S-, - OC(O)-, -C(O)O-, -C(O)-, -S(O)-, -S(O) ₂ -, -N(R)S(O) ₂ -, -S(O) ₂ N(R)-, - N(R)C(O)-, -C(O)N(R)-, - OC(O)N(R)-, –N(R)C(O)O-, wherein each –Cy– is independently an optionally substituted bivalent ring selected from phenylenyl, an 8-10 membered bicyclic arylenyl, a 4-7 membered saturated or partially unsaturated carbocyclylenyl, a 4-11 membered saturated or partially unsaturated spiro carbocyclylenyl, an 8-10 membered bicyclic saturated or partially unsaturated carbocyclylenyl, a 4-7 membered saturated or partially unsaturated heterocyclylenyl having 1-2 heteroatoms independently selected from nitrogen, oxygen, and sulfur, a 4-11 membered saturated or partially unsaturated spiro heterocyclylenyl having 1-2 heteroatoms independently selected from nitrogen, oxygen, and sulfur, an 8- 10 membered bicyclic saturated or partially unsaturated heterocyclylenyl having 1-2 heteroatoms independently selected from nitrogen, oxygen, and sulfur, a 5-6 membered heteroarylenyl having 1-4 heteroatoms independently selected from nitrogen, oxygen, and sulfur, or an 8-10 membered bicyclic heteroarylenyl having 1-5 heteroatoms independently selected from nitrogen, oxygen, or sulfur, and wherein r is 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10; X ¹ is a bivalent moiety selected from a covalent bond, –CH ₂ –, –CHCF ₃ –, –SO ₂ –, – S(O)–, –P(O)R–, – P(O)OR–, –P(O)NR ₂ –, –C(O)–, –C(S)–, or ; X ² is a carbon atom or silicon atom; X ³ is a bivalent moiety selected from –CR2–, –NR–, –O–, –S–, or –Si(R2)–; R ¹ is hydrogen, deuterium, halogen, –CN, –OR, –SR, –S(O)R, –S(O) ₂ R, –N(R) ₂ , –P(O)(OR) ₂ , – P(O)(NR2)OR, –P(O)(NR2) ₂ , –Si(OH) ₂ R, –Si(OH)(R) ₂ , –Si(R) ₃ , or an optionally substituted C _1-4 aliphatic; each R ² is independently hydrogen, deuterium, –R ⁶ , halogen, –CN, –NO ₂ , –OR, -SR, - N(R) ₂ , - Si(R) ₃ , -S(O) ₂ R, -S(O) ₂ N(R) ₂ , -S(O)R, -C(O)R, -C(O)OR, –C(O)N(R) ₂ , - C(O)N(R)OR, - C(R) ₂ N(R)C(O)R, -C(R) ₂ N(R)C(O)N(R) ₂ , -OC(O)R, -OC(O)N(R) ₂ , - OP(O)R ₂ , -OP(O)(OR) ₂ , - OP(O)(OR)(NR ₂ ), -OP(O)(NR ₂ ) ₂ -, -N(R)C(O)OR, -N(R)C(O)R, - N(R)C(O)N(R) ₂ , –N(R)S(O) ₂ R, - NP(O)R ₂ , -N(R)P(O)(OR) ₂ , -N(R)P(O)(OR)(NR ₂ ), - N(R)P(O)(NR2) ₂ , or –N(R)S(O) ₂ R; Ring B is a fused ring selected from 6-membered aryl, 6-membered heteroaryl containing 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur, 5 to 7- membered saturated or partially unsaturated carbocyclyl, 5 to 7-membered saturated or partially unsaturated heterocyclyl with 1-3 heteroatoms independently selected from boron, nitrogen, oxygen, silicon, or sulfur, or 5-membered heteroaryl with 1-4 heteroatoms independently selected from nitrogen, oxygen or sulfur; R ³ is selected from hydrogen, halogen, –OR, –N(R) ₂ , or –SR; each R ⁴ is independently hydrogen, –R ⁶ , halogen, –CN, –NO ₂ , –OR, - SR, -NR2, - S(O) ₂ R, -S(O) ₂ NR ₂ , -S(O)R, -C(O)R, -C(O)OR, – C(O)NR ₂ , -C(O)N(R)OR, -OC(O)R, - OC(O)NR ₂ , -N(R)C(O)OR, -N(R)C(O)R, -N(R)C(O)NR ₂ , or –N(R)S(O) ₂ R; R ⁵ is hydrogen, C _1-4 aliphatic, or –CN; each R ⁶ is independently an optionally substituted group selected from C _1-6 aliphatic, phenyl, a 4-7 membered saturated or partially unsaturated heterocyclic ring having 1-2 heteroatoms independently selected from nitrogen, oxygen, and sulfur, and a 5-6 membered heteroaryl ring having 1-4 heteroatoms independently selected from nitrogen, oxygen, and sulfur; L ¹ is a covalent bond or a C _1-3 bivalent straight or branched saturated or unsaturated hydrocarbon chain wherein 1-2 methylene units of the chain are independently and optionally replaced with -O-, -C(O)- , -C(S)-, -C(R) ₂ -, -CF(R)-, -C(F) ₂ -, -N(R)-, -S-, -S(O) ₂ - or -(C)=CH- ; m is 0, 1, 2, 3 or 4; each R is independently hydrogen, or an optionally substituted group selected from C _{1– 6} aliphatic, phenyl, a 4-7 membered saturated or partially unsaturated heterocyclic having 1-2 heteroatoms independently selected from nitrogen, oxygen, and sulfur, and a 5-6 membered heteroaryl ring having 1-4 heteroatoms independently selected from nitrogen, oxygen, and sulfur, or: two R groups on the same nitrogen are optionally taken together with their intervening atoms to form a 4-7 membered saturated, partially unsaturated, or heteroaryl ring having 0-3 heteroatoms, in addition to the nitrogen, independently selected from nitrogen, oxygen, and sulfur; and Ring A is a bi- or tricyclic ring that is:

. [0264] Where a point of attachment of –(R ² )m is depicted on Ring B, it is intended, and one of ordinary skill in the art would appreciate, that the point of attachment of –(R ² )m may be on Ring A and may also be at any available carbon or nitrogen atom on Ring A including the ring to which Ring B is fused. Where - R ² is attached to a nitrogen atom bound to R ⁴ or R ⁵ , R ⁴ or R ⁵ is absent and -R ² takes the place of the R ⁴ or R ⁵ group. [0265] In some embodiments, L is a covalent bond. In some embodiments, each –Cy– is independently an optionally substituted bivalent phenylenyl. In some embodiments, each – Cy– is independently an optionally substituted 8-10 membered bicyclic arylenyl. In some embodiments, each –Cy– is independently an optionally substituted 4-7 membered saturated or partially unsaturated carbocyclylenyl. In some embodiments, each –Cy– is independently an optionally substituted 4-7 membered saturated or partially unsaturated spiro carbocyclylenyl. In some embodiments, each –Cy– is independently an optionally substituted 8-10 membered bicyclic saturated or partially unsaturated carbocyclylenyl. In some embodiments, each –Cy– is independently an optionally substituted 4-7 membered saturated or partially unsaturated heterocyclylenyl having 1-2 heteroatoms independently selected from nitrogen, oxygen, and sulfur. In some embodiments, each –Cy– is independently an optionally substituted 4-7 membered saturated or partially unsaturated spiro heterocyclylenyl having 1-2 heteroatoms independently selected from nitrogen, oxygen, and sulfur. In some embodiments, each –Cy– is independently an optionally substituted 8-10 membered bicyclic saturated or partially unsaturated heterocyclylenyl having 1-2 heteroatoms independently selected from nitrogen, oxygen, and sulfur. In some embodiments, each –Cy– is independently an optionally substituted 5-6 membered heteroarylenyl having 1-4 heteroatoms independently selected from nitrogen, oxygen, and sulfur. In some embodiments, each –Cy– is independently an optionally substituted 8-10 membered bicyclic heteroarylenyl having 1-5 heteroatoms independently selected from nitrogen, oxygen, or sulfur. [0266] In embodiments, a linker is as described at, e.g., paragraphs [00478]-[0486] and Table 1 or Table B of WO2022178532A1 (e.g., exemplified linkers (1)-(650) of Table B). [0267] In embodiments, -L ^P -E comprises, corresponds to, or is derived from a moiety found in any of the exemplary compounds of Table 1 of WO2022178532A1 (e.g., a moiety found in any of Compounds I-1 to I-100 as described therein). [0268] In certain embodiments, an L ^P -E moiety comprises, corresponds to, or is derived from that present in KT-474, including any fragments thereof. [0269] In certain embodiments, an L ^P -E moiety comprises, corresponds to, or is derived from that present in KT-413, including any fragments thereof. [0270] In certain embodiments, an L ^P -E moiety comprises, corresponds to, or is derived from that present in KT-333, including any fragments thereof. Exemplary Group 3 [0271] In certain embodiments, L ^P -E moieties include any of the PROTAC degraders described in US20220098194A1, which is incorporated herein by reference in its entirety, as well any moieties corresponding to L ^P and/or E described therein. In embodiments, -L ^P -E comprises, corresponds to, or is derived from a moiety described therein, including any fragments thereof. [0272] In certain embodiments, L ^P -E moieties include any of the PROTAC degraders described in WO2022081927A1, which is incorporated herein by reference in its entirety, as well any moieties corresponding to L ^P and/or E described therein. In embodiments, -L ^P -E comprises, corresponds to, or is derived from a moiety described therein, including any fragments thereof. [0273] In certain embodiments, L ^P -E moieties include any of the PROTAC degraders described in WO2022081925A1, which is incorporated herein by reference in its entirety, as well any moieties corresponding to L ^P and/or E described therein. In embodiments, -L ^P -E comprises, corresponds to, or is derived from a moiety described therein, including any fragments thereof. [0274] In certain embodiments, L ^P -E moieties include any of the PROTAC degraders described in WO2022081928A1, which is incorporated herein by reference in its entirety, as well any moieties corresponding to L ^P and/or E described therein. In embodiments, -L ^P -E comprises, corresponds to, or is derived from a moiety described therein, including any fragments thereof. [0275] In certain embodiments, L ^P -E moieties include any of the PROTAC degraders described in US11407732B1, which is incorporated herein by reference in its entirety, as well any moieties corresponding to L ^P and/or E described therein. In embodiments, -L ^P -E comprises, corresponds to, or is derived from a moiety described therein, including any fragments thereof. [0276] In certain embodiments, L ^P -E moieties include any of the PROTAC degraders described in WO2022032132A1, which is incorporated herein by reference in its entirety, as well any moieties corresponding to L ^P and/or E described therein. In embodiments, -L ^P -E comprises, corresponds to, or is derived from a moiety described therein, including any fragments thereof. [0277] In certain embodiments, L ^P -E moieties include any of the PROTAC degraders described in WO2022032026A1, which is incorporated herein by reference in its entirety, as well any moieties corresponding to L ^P and/or E described therein. In embodiments, -L ^P -E comprises, corresponds to, or is derived from a moiety described therein, including any fragments thereof. [0278] In certain embodiments, L ^P -E moieties include any of the PROTAC degraders described in WO2021255213A1, which is incorporated herein by reference in its entirety, as well any moieties corresponding to L ^P and/or E described therein. In embodiments, -L ^P -E comprises, corresponds to, or is derived from a moiety described therein, including any fragments thereof. [0279] In certain embodiments, L ^P -E moieties include any of the PROTAC degraders described in WO2021255212A1, which is incorporated herein by reference in its entirety, as well any moieties corresponding to L ^P and/or E described therein. In embodiments, -L ^P -E comprises, corresponds to, or is derived from a moiety described therein, including any fragments thereof. [0280] In certain embodiments, L ^P -E moieties include any of the PROTAC degraders described in US20210198256A1, which is incorporated herein by reference in its entirety, as well any moieties corresponding to L ^P and/or E described therein. In embodiments, -L ^P -E comprises, corresponds to, or is derived from a moiety described therein, including any fragments thereof. [0281] In certain embodiments, L ^P -E moieties include any of the PROTAC degraders described in WO2021127561A1, which is incorporated herein by reference in its entirety, as well any moieties corresponding to L ^P and/or E described therein. In embodiments, -L ^P -E comprises, corresponds to, or is derived from a moiety described therein, including any fragments thereof. [0282] In certain embodiments, L ^P -E moieties include any of the PROTAC degraders described in US20210070763A1, which is incorporated herein by reference in its entirety, as well any moieties corresponding to L ^P and/or E described therein. In embodiments, -L ^P -E comprises, corresponds to, or is derived from a moiety described therein, including any fragments thereof. [0283] In certain embodiments, L ^P -E moieties include any of the PROTAC degraders described in WO2021083949A1, which is incorporated herein by reference in its entirety, as well any moieties corresponding to L ^P and/or E described therein. In embodiments, -L ^P -E comprises, corresponds to, or is derived from a moiety described therein, including any fragments thereof. [0284] In certain embodiments, L ^P -E moieties include any of the PROTAC degraders described in WO2021086785A1, which is incorporated herein by reference in its entirety, as well any moieties corresponding to L ^P and/or E described therein. In embodiments, -L ^P -E comprises, corresponds to, or is derived from a moiety described therein, including any fragments thereof. [0285] In certain embodiments, L ^P -E moieties include any of the PROTAC degraders described in US20210032245A1, which is incorporated herein by reference in its entirety, as well any moieties corresponding to L ^P and/or E described therein. In embodiments, -L ^P -E comprises, corresponds to, or is derived from a moiety described therein, including any fragments thereof. [0286] In certain embodiments, L ^P -E moieties include any of the PROTAC degraders described in US20210009559A1, which is incorporated herein by reference in its entirety, as well any moieties corresponding to L ^P and/or E described therein. In embodiments, -L ^P -E comprises, corresponds to, or is derived from a moiety described therein, including any fragments thereof. [0287] In certain embodiments, L ^P -E moieties include any of the PROTAC degraders described in US20200361930A1, which is incorporated herein by reference in its entirety, as well any moieties corresponding to L ^P and/or E described therein. In embodiments, -L ^P -E comprises, corresponds to, or is derived from a moiety described therein, including any fragments thereof. [0288] In certain embodiments, L ^P -E moieties include any of the PROTAC degraders described in US20220251061A1, which is incorporated herein by reference in its entirety, as well any moieties corresponding to L ^P and/or E described therein. In embodiments, -L ^P -E comprises, corresponds to, or is derived from a moiety described therein, including any fragments thereof. [0289] In certain embodiments, L ^P -E moieties include any of the PROTAC degraders described in US10905768B1, which is incorporated herein by reference in its entirety, as well any moieties corresponding to L ^P and/or E described therein. In embodiments, -L ^P -E comprises, corresponds to, or is derived from a moiety described therein, including any fragments thereof. [0290] In certain embodiments, L ^P -E moieties include any of the PROTAC degraders described in WO2020181232A1, which is incorporated herein by reference in its entirety, as well any moieties corresponding to L ^P and/or E described therein. In embodiments, -L ^P -E comprises, corresponds to, or is derived from a moiety described therein, including any fragments thereof. [0291] In certain embodiments, L ^P -E moieties include any of the PROTAC degraders described in US20200207733A1, which is incorporated herein by reference in its entirety, as well any moieties corresponding to L ^P and/or E described therein. In embodiments, -L ^P -E comprises, corresponds to, or is derived from a moiety described therein, including any fragments thereof. [0292] In certain embodiments, L ^P -E moieties include any of the PROTAC degraders described in US11254672B2, which is incorporated herein by reference in its entirety, as well any moieties corresponding to L ^P and/or E described therein. In embodiments, -L ^P -E comprises, corresponds to, or is derived from a moiety described therein, including any fragments thereof. [0293] In certain embodiments, L ^P -E moieties include any of the PROTAC degraders described in US20200207783A1, which is incorporated herein by reference in its entirety, as well any moieties corresponding to L ^P and/or E described therein. In embodiments, -L ^P -E comprises, corresponds to, or is derived from a moiety described therein, including any fragments thereof. [0294] In certain embodiments, L ^P -E moieties include any of the PROTAC degraders described in WO2020132561A1, which is incorporated herein by reference in its entirety, as well any moieties corresponding to L ^P and/or E described therein. In embodiments, -L ^P -E comprises, corresponds to, or is derived from a moiety described therein, including any fragments thereof. [0295] In certain embodiments, L ^P -E moieties include any of the PROTAC degraders described in US20200140456A1, which is incorporated herein by reference in its entirety, as well any moieties corresponding to L ^P and/or E described therein. In embodiments, -L ^P -E comprises, corresponds to, or is derived from a moiety described therein, including any fragments thereof. [0296] In certain embodiments, L ^P -E moieties include any of the PROTAC degraders described in US10849982B2, which is incorporated herein by reference in its entirety, as well any moieties corresponding to L ^P and/or E described therein. In embodiments, -L ^P -E comprises, corresponds to, or is derived from a moiety described therein, including any fragments thereof. [0297] In certain embodiments, L ^P -E moieties include any of the PROTAC degraders described in US20190076539A1, which is incorporated herein by reference in its entirety, as well any moieties corresponding to L ^P and/or E described therein. In embodiments, -L ^P -E comprises, corresponds to, or is derived from a moiety described therein, including any fragments thereof. [0298] In certain embodiments, L ^P -E moieties include any of the PROTAC degraders described in US20190070185A1, which is incorporated herein by reference in its entirety, as well any moieties corresponding to L ^P and/or E described therein. In embodiments, -L ^P -E comprises, corresponds to, or is derived from a moiety described therein, including any fragments thereof. [0299] In certain embodiments, L ^P -E moieties include any of the PROTAC degraders described in US11185592B2, which is incorporated herein by reference in its entirety, as well any moieties corresponding to L ^P and/or E described therein. In embodiments, -L ^P -E comprises, corresponds to, or is derived from a moiety described therein, including any fragments thereof. [0300] In embodiments, a linker L ^P moiety is a chain of 2 to 14, 15, 16, 17, 18 or 20 or more carbon atoms of which one or more carbons can be replaced by a heteroatom such as O, N, S, or P. In certain embodiments the chain has 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20 contiguous atoms in the chain. For example, the chain may include 1 or more ethylene glycol units that can be contiguous, partially contiguous or non-contiguous (for example, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12 ethylene glycol units). In certain embodiments, the chain has at least 1, 2, 3, 4, 5, 6, 7, or 8 contiguous chains which can have branches which can be independently alkyl, heteroalkyl, aryl, heteroaryl, alkenyl, or alkynyl, aliphatic, heteroaliphatic, cycloalkyl or heterocyclic substituents. [0301] In embodiments, a linker L ^P moiety can include or be comprised of one or more of ethylene glycol, propylene glycol, lactic acid and/or glycolic acid. In general, propylene glycol adds hydrophobicity, while propylene glycol adds hydrophilicity. Lactic acid segments tend to have a longer half-life than glycolic acid segments. Block and random lactic acid-co-glycolic acid moieties, as well as ethylene glycol and propylene glycol, are known in the art to be pharmaceutically acceptable and can be modified or arranged to obtain the desired half-life and hydrophilicity. In certain aspects, these units can be flanked or interspersed with other moieties, such as aliphatic, including alkyl, heteroaliphatic, aryl, heteroaryl, heterocyclic, cycloalkyl, etc., as desired to achieve the appropriate drug properties. [0302] In embodiments, a linker L ^P moiety is selected from the following formulas:

wherein: X ¹ and X ² are independently selected from bond, NH, NR ²⁵ , CH ₂ , CHR ²⁵ , C(R ²⁵ ) ₂ , O, and S; R ²⁰ , R ²¹ , R ²² , R ²³ , and R ²⁴ are independently selected from bond, alkyl, —C(O)— — C(O)O—, —OC(O)—, —C(O)alkyl, —C(O)Oalkyl, —C(S)—, —SO ₂ —, —S(O)—, — C(S)—, —C(O)NH—, —NHC(O)—, —N(alkyl)C(O)—, —C(O)N(alkyl)-, —O—, —S—, — NH—, —N(alkyl)-, —CH(—O—R ²⁶ )—, —CH(—NHR ²⁵ )—, —CH(—NH ₂ )—, —CH(— NR ²⁵ ₂ )—, —C(—O—R ²⁶ )alkyl-, —C(—NHR ²⁵ )alkyl-, —C(—NH ₂ )alkyl-, —C(— NR ²⁵ ₂ )alkyl-, —C(R ⁴ R ⁴ )—, -alkyl(R ²⁷ )-alkyl(R ²⁸ )—, —C(R ²⁷ R ²⁸ )—, —P(O)(OR ²⁶ )O—, — P(O)(OR ²⁶ )—, —NHC(O)NH—, —N(R ²⁵ )C(O)N(R ²⁵ )—, —N(H)C(O)N(R ²⁵ )—, polyethylene glycol, poly(lactic-co-glycolic acid), alkene, haloalkyl, alkoxy, and alkyne; or R ²⁰ , R ²¹ , R ²² , R ²³ , and R ²⁴ can in addition to those above be independently selected from heteroarylalkyl, aryl, arylalkyl, heterocycle, aliphatic, heteroaliphatic, heteroaryl, polypropylene glycol, lactic acid, glycolic acid, carbocycle, or —O—(CH ₂ )1-12—O—, — NH—(CH ₂ ) _1-12 —NH—, —NH—(CH ₂ ) _1-12 —O—, or —O—(CH ₂ ) _1-12 —NH—, —S—(CH ₂ ) _{1- 12} —O—, —O—(CH ₂ ) _1-12 —S—, —S—(CH ₂ ) _1-12 —S—, —S—(CH ₂ ) _1-12 —NH—, —NH— (CH ₂ ) _1-12 —S—, (and wherein the 1-12 can be independently 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12, and wherein one or more of the CH ₂ or NH can be modified by substitution of a H for a methyl, ethyl, cyclopropyl, F (if on carbon), etc, as described herein), and optionally, a heteroatom, heteroalkyl, aryl, heteroaryl or cycloaliphatic group is interspersed in the chain). Certain nonlimiting examples include —O—CH(CH ₃ )—CH(CH ₃ )CH—O—, —O—CH ₂ — CH(CH ₃ )CH—O—, —O—CH(CH ₃ )—CH ₂ CH—O—, etc. each of which R ²⁰ , R ²¹ , R ²² , R ²³ , and R ²⁴ is optionally substituted with one or more substituents selected from R ¹⁰¹ or alternatively as described in Section 1. Definitions; R ²⁵ is selected at each instance from: alkyl, —C(O)H, —C(O)OH, —C(O)alkyl, — C(O)Oalkyl, alkenyl, or alkynyl or alternatively can be aliphatic, heteroaliphatic, aryl, heteroaryl or heterocyclic; R ²⁶ is hydrogen, alkyl, silane, arylalkyl, heteroarylalkyl, alkene, and alkyne; or in addition to these can also be selected from aryl, heteroaryl, heterocyclic, aliphatic and heteroaliphatic; R ²⁷ and R ²⁸ are independently selected from hydrogen, alkyl, amine, or together with the carbon atom to which they are attached, form C(O), C(S), C═CH ₂ , a C ₃ - C ₆ spirocarbocycle, or a 4-, 5-, or 6-membered spiroheterocycle comprising 1 or 2 heteroatoms selected from N and O, or form a 1 or 2 carbon bridged ring; R ¹⁰¹ is independently selected at each occurrence from hydrogen, alkyl, alkene, alkyne, haloalkyl, alkoxy, hydroxyl, aryl, heteroaryl, heterocycle, arylalkyl, heteroarylalkyl, heterocycloalkyl, aryloxy, heteroaryloxy, CN, —COOalkyl, COOH, NO ₂ , F, Cl, Br, I, CF ₃ , NH ₂ , NHalkyl, N(alkyl) ₂ , NR ²⁵ R ²⁵ , NHR ²⁵ , aliphatic, heteroaliphatic, and COR ⁴ ; and R ⁴ is selected from hydrogen, alkyl, aliphatic, heteroaliphatic, aryl, heteroaryl, carbocyclic, hydroxyl, alkoxy, amine, —NHalkyl, or —Nalkyl ₂ . [0303] In embodiments, a linker L ^P moiety is an optionally substituted (poly)ethylene glycol having at least 1, at least 2, at least 3, at least 4, at least 5, at least 6, at least 7, at least 8, at least 9, at least 10, ethylene glycol units, or optionally substituted alkyl groups interspersed with optionally substituted, O, N, S, P or Si atoms. In certain embodiments, the Linker is flanked, substituted, or interspersed with an aryl, phenyl, benzyl, alkyl, alkylene, or heterocycle group. In certain embodiments, the Linker may be asymmetric or symmetrical. In some embodiments, the Linker is a substituted or unsubstituted polyethylene glycol group ranging in size from about 1 to about 12 ethylene glycol units, between 1 and about 10 ethylene glycol units, about 2 about 6 ethylene glycol units, between about 2 and 5 ethylene glycol units, between about 2 and 4 ethylene glycol units. In any of the embodiments of the compounds described herein, the linker L ^P moiety may be any suitable moiety as described herein. [0304] In embodiments, the linker L ^P moiety is selected from: —NR ⁶¹ (CH ₂ ) _n1 -(lower alkyl)-, —NR ⁶¹ (CH ₂ ) _n1 -(lower alkoxyl)-, —NR ⁶¹ (CH ₂ ) _n1 -(lower alkoxyl)-OCH ₂ —, —NR ⁶¹ (CH ₂ ) _n1 - (lower alkoxyl)-(lower alkyl)-OCH ₂ —, —NR ⁶¹ (CH ₂ ) _n1 -(cycloalkyl)-(lower alkyl)-OCH ₂ —, —NR ⁶¹ (CH ₂ ) _n1 -(heterocycloalkyl)-, —NR ⁶¹ (CH ₂ CH ₂ O) _n1 -(lower alkyl)-O—CH ₂ —, — NR ⁶¹ (CH ₂ CH ₂ O) _n1 -(heterocycloalkyl)-O—CH ₂ —, —NR ⁶¹ (CH ₂ CH ₂ O) _n1 -Aryl-O—CH ₂ —, — NR ⁶¹ (CH ₂ CH ₂ O) _n1 -(heteroaryl)-O—CH ₂ —, —NR ⁶¹ (CH ₂ CH ₂ O) _n1 -(cycloalkyl)-O-(heteroaryl)- O—CH ₂ —, —NR ⁶¹ (CH ₂ CH ₂ O) _n1 -(cycloalkyl)-O-Aryl-O—CH ₂ —, —NR ⁶¹ (CH ₂ CH ₂ O) _n1 - (lower alkyl)-NH-Aryl-O— CH ₂ —, —NR ⁶¹ (CH ₂ CH ₂ O) _n1 -(lower alkyl)-O-Aryl-CH ₂ , — NR ⁶¹ (CH ₂ CH ₂ O)n-cycloalkyl-O-Aryl-, —NR ⁶¹ (CH ₂ CH ₂ O) _n1 -cycloalkyl-O-heteroaryl-, — NR ⁶¹ (CH ₂ CH ₂ ) _n1 -(cycloalkyl)-O-(heterocycle)-CH ₂ , —NR ⁶¹ (CH ₂ CH ₂ ) _n1 -(heterocycle)- (heterocycle)-CH ₂ , and —NR ⁶¹ -(heterocycle)-CH ₂ ; wherein n1 is 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10; and R ⁶¹ is H, methyl, or ethyl. [0305] In embodiments, the linker L ^P moiety is selected from: —N(R ⁶¹ )—(CH ₂ ) _m1 —O(CH ₂ ) _n2 —O(CH ₂ ) _o1 —O(CH ₂ ) _p1 —O(CH ₂ ) _q1 —O(CH ₂ ) _r1 —OCH ₂ —O— (CH ₂ ) _m1 —O(CH ₂ ) _n2 —O(CH ₂ ) _o1 —O(CH ₂ ) _p1 —O(CH ₂ ) _q1 —O(CH ₂ ) _r1 —OCH ₂ —, —O— (CH ₂ ) _m1 —O(CH ₂ ) _n2 —O(CH ₂ ) _o1 —O(CH ₂ ) _p1 —O(CH ₂ ) _q1 —O(CH ₂ ) _r1 —O—; —N(R ⁶¹ )—(CH ₂ ) _m1 —O(CH ₂ ) _n2 —O(CH ₂ ) _o1 —O(CH ₂ ) _p1 —O(CH ₂ ) _q1 —O(CH ₂ ) _r1 —O—; —(CH ₂ ) _m1 —O(CH ₂ ) _n2 —O(CH ₂ ) _o1 —O(CH ₂ ) _p1 —O(CH ₂ ) _q1 —O(CH ₂ ) _r1 —O—; —(CH ₂ ) _m1 —O(CH ₂ ) _n2 —O(CH ₂ ) _o1 —O(CH ₂ ) _p1 —O(CH ₂ ) _q1 —O(CH ₂ ) _r1 —OCH ₂ —; —O(CH ₂ ) _m1 O(CH ₂ ) _n2 O(CH ₂ ) _p1 O(CH ₂ ) _q1 OCH ₂ —; and —O(CH ₂ ) _m1 O(CH ₂ ) _n2 O(CH ₂ ) _p1 O(CH ₂ ) _q1 OCH ₂ —; wherein m1, n2, o1, p1, q1, and r1 are independently 1, 2, 3, 4, or 5; and R ⁶¹ is H, methyl, or ethyl. [0306] In certain embodiments, a L ^P moiety includes any of the strctures described in US11185592B2 at cols.97-148. [0307] In certain embodiments, an E moiety includes any of the strctures described in US11185592B2 as the fragments according to Formula (I) and Formula (II) cols.61-74 or according to Formula III and IV at cols.74-84. [0308] In certain embodiments, L ^P -E moieties include any of the PROTAC degraders described in US20200308171A1, which is incorporated herein by reference in its entirety, as well any moieties corresponding to L ^P and/or E described therein. In embodiments, -L ^P -E comprises, corresponds to, or is derived from a moiety described therein, including any fragments thereof. [0309] For example, L ^P , E, and/or L ^P -E moieties include those according to the following formula, where Y is covalently attached to the the Ligand moiety, Y is absent or heterocyclyl (e.g., pyrrolidinyl); and L is selected from the group consisting of i) —C(═O)—(CH ₂ ) _2-10 —NH—, in particular —C(═O)—(CH ₂ ) ₅ —NH—; ii) —(CH ₂ ) _2-10 —NH—, in particular —(CH ₂ ) ₆ —NH—, —(CH ₂ ) ₅ —NH— or — (CH ₂ ) ₄ —NH—; iii) —(CH ₂ ) _2-10 -heterocyclyl-, in particular a. —(CH ₂ ) _2-10 -piperidyl-, in particular —(CH ₂ ) ₄ -piperidyl-, —(CH ₂ ) ₃ - piperidyl- or —(CH ₂ ) ₂ -piperidyl-; or b. —(CH ₂ ) _2-10 -azetidinyl-, in particular —(CH ₂ ) ₃ -azetidinyl- or —(CH ₂ ) ₂ - azetidinyl-; iv) —C(═O)-heterocyclyl-(CH ₂ ) _2-10 —NH—, in particular —C(═O)-piperazinyl- (CH ₂ ) _2-10 —NH—, more particular —C(═O)-piperazinyl-(CH ₂ ) ₄ —NH—; v) —(CH ₂ ) _2-10 —O-heterocyclyl-, in particular a. —(CH ₂ ) _2-10 —O-piperidyl-, in particular —(CH ₂ ) ₃ —O-piperidyl-; or b. —(CH ₂ ) _2-10 —O-azetidinyl-, in particular —(CH ₂ ) ₃ —O-azetidinyl-; and vi) —(CH ₂ ) _2-10 —C _3-6 cycloalkyl-, in particular —(CH ₂ ) ₃ -cyclohexyl; [0310] In certain embodiments, an L ^P -E moiety comprises, corresponds to, or is derived from that present in CFT8919, including any fragments thereof. [0311] In certain embodiments, an L ^P -E moiety comprises, corresponds to, or is derived from that present in CFT8634, including any fragments thereof. In embodiments, an L ^P -E moiety has a structure according to (D48), (D48)’, or (D48)”. Exemplary Group 4 [0312] In certain embodiments, an L ^P -E moiety comprises, corresponds to, or is derived from that present in DT2216, including any fragments thereof. [0313] In certain embodiments, an L ^P -E moiety comprises, corresponds to, or is derived from that present in AC682, including any fragments thereof. [0314] In certain embodiments, an L ^P -E moiety comprises, corresponds to, or is derived from that present in CC-94676, including any fragments thereof. [0315] In certain embodiments, an L ^P -E moiety comprises, corresponds to, or is derived from that present in FHD-609, including any fragments thereof. [0316] In certain embodiments, an L ^P -E moiety comprises, corresponds to, or is derived from that present in NX-2127, including any fragments thereof. [0317] In certain embodiments, an L ^P -E moiety comprises, corresponds to, or is derived from that present in NX-5948, including any fragments thereof. [0318] In certain embodiments, an L ^P -E moiety comprises, corresponds to, or is derived from that present in CG001419, including any fragments thereof. Deuterated Compounds [0319] Compounds described herein can comprise atoms that exhibit their natural isotopic abundances, or one or more of the atoms may be artificially enriched in a particular isotope having the same atomic number, but an atomic mass or mass number different from the atomic mass or mass number predominately found in nature. The term “isotopologue” refers to a species that has the same chemical structure and formula as a specific compound provided herein, with the exception of the positions of isotopic substitution and/or level of isotopic enrichment at one or more positions, e.g., hydrogen vs. deuterium. The present invention is meant to include all suitable isotopic variations of the compounds of the compounds described herein. For example, different isotopic forms of hydrogen (H) include protium ( ¹ H), deuterium ( ² H), and tritium ( ³ H), as well as compositions enriched in isotopologues of any compound described herein. [0320] In embodiments, one or more of the hydrogens of the compounds described herein is replaced by a deuterium. When a position is designated as “H” or “hydrogen”, the position is understood to have hydrogen at its natural abundance isotopic composition. When a position is designated as “ ² H” or “deuterium”, the position is understood to have deuterium at an abundance that is at least 3340 times greater than the natural abundance of deuterium, which is 0.015% (i.e., the term “ ² H” or “deuterium” indicates at least 50.1% incorporation of deuterium). Accordingly, the invention also features compositions enriched in deuterated compounds. [0321] In embodiments, compositions of any compound provided herein may have an isotopic enrichment factor for each deuterium present at a site designated as a potential site of deuteration on the compound of at least 3500 (52.5% deuterium incorporation), at least 4000 (60% deuterium incorporation), at least 4500 (67.5% deuterium incorporation), at least 5000 (75% deuterium), at least 5500 (82.5% deuterium incorporation), at least 6000 (90% deuterium incorporation), at least 6333.3 (95% deuterium incorporation), at least 6466.7 (97% deuterium incorporation), at least 6600 (99% deuterium incorporation), or at least 6633.3 (99.5% deuterium incorporation). Synthetic Methods [0322] Compounds described herein can be prepared according to methods known in the art. For example, the exemplary synthetic methods described in the instant Examples can be used to prepare still other compounds of the invention. [0323] Accordingly, disclosed compounds can generally be synthesized by an appropriate combination of generally well known synthetic methods. Techniques useful in synthesizing these chemical entities are both readily apparent and accessible to those of skill in the relevant art, based on the instant disclosure. Many of the optionally substituted starting compounds and other reactants are commercially available, e.g., from Aldrich Chemical Company (Milwaukee, Wis.) or can be readily prepared by those skilled in the art using commonly employed synthetic methodology. [0324] Pharmaceutical Compositions [0325] In another exemplary aspect, the invention features pharmaceutical compositions comprising any compound herein, or a pharmaceutically acceptable form thereof. In embodiments, a pharmaceutical composition comprises a therapeutically effective amount of any compound described herein, or any pharmaceutically acceptable form thereof. [0326] In embodiments, a pharmaceutically acceptable form of a compound includes any pharmaceutically acceptable salts, hydrates, solvates, isomers, prodrugs, and isotopically labeled derivatives thereof. [0327] In embodiments, a pharmaceutical composition comprises any compound described herein, or a pharmaceutically acceptable salt thereof. [0328] In embodiments, a pharmaceutical composition comprises a pharmaceutically acceptable excipient. [0329] For the purposes of the present invention the term “excipient” and “carrier” are used interchangeably throughout the description of the present invention and said terms are defined herein as, “ingredients which are used in the practice of formulating a safe and effective pharmaceutical composition.” [0330] The formulator will understand that excipients are used primarily to serve in delivering a safe, stable, and functional pharmaceutical, serving not only as part of the overall vehicle for delivery but also as a means for achieving effective absorption by the recipient of the active ingredient. An excipient may fill a role as simple and direct as being an inert filler, or an excipient as used herein may be part of a pH stabilizing system or coating to insure delivery of the ingredients safely to the stomach. The formulator can also take advantage of the fact the compounds of the present invention have improved cellular potency, pharmacokinetic properties, as well as improved oral bioavailability. [0331] Accordingly, in some embodiments, provided herein are pharmaceutical compositions comprising one or more compounds as disclosed herein, or a pharmaceutically acceptable form thereof (e.g., pharmaceutically acceptable salts, hydrates, solvates, isomers, prodrugs, and isotopically labeled derivatives), and one or more pharmaceutically acceptable excipients, carriers, including inert solid diluents and fillers, diluents, including sterile aqueous solution and various organic solvents, permeation enhancers, solubilizers and adjuvants. In some embodiments, a pharmaceutical composition described herein includes a second active agent such as an additional therapeutic agent, (e.g., a chemotherapeutic). [0332] Accordingly, the present teachings also provide pharmaceutical compositions that include at least one compound described herein, or any pharmaceutically salt thereof thereof, and one or more pharmaceutically acceptable carriers, excipients, or diluents. Examples of such carriers are well known to those skilled in the art and can be prepared in accordance with acceptable pharmaceutical procedures, such as, for example, those described in Remington’s Pharmaceutical Sciences, 17th edition, ed. Alfonoso R. Gennaro, Mack Publishing Company, Easton, PA (1985), the entire disclosure of which is incorporated by reference herein for all purposes. As used herein, “pharmaceutically acceptable” refers to a substance that is acceptable for use in pharmaceutical applications from a toxicological perspective and does not adversely interact with the active ingredient. Accordingly, pharmaceutically acceptable carriers are those that are compatible with the other ingredients in the composition and are biologically acceptable. Supplementary active ingredients can also be incorporated into the pharmaceutical compositions. [0333] Compounds of the present teachings can be administered orally or parenterally, neat or in combination with conventional pharmaceutical carriers. Applicable solid carriers can include one or more substances which can also act as flavoring agents, lubricants, solubilizers, suspending agents, fillers, glidants, compression aids, binders or tablet-disintegrating agents, or encapsulating materials. The compounds can be formulated in conventional manner, for example, in a manner similar to that used for known 5-hydroxytryptamine receptor 7 activity modulators. Pharmaceutical compositions in the form of oral formulations containing a compound disclosed herein can comprise any conventionally used oral form, including tablets, capsules, buccal forms, troches, lozenges and oral liquids, suspensions or solutions. In powders, the carrier can be a finely divided solid, which is an admixture with a finely divided compound. In tablets, a compound disclosed herein can be mixed with a carrier having the necessary compression properties in suitable proportions and compacted in the shape and size desired. The powders and tablets can contain up to 99 % of the compound. [0334] Capsules can contain mixtures of one or more compound(s) disclosed herein with inert filler(s) and/or diluent(s) such as pharmaceutically acceptable starches (e.g., corn, potato or tapioca starch), sugars, artificial sweetening agents, powdered celluloses (e.g., crystalline and microcrystalline celluloses), flours, gelatins, gums, and the like. [0335] Useful tablet formulations can be made by conventional compression, wet granulation or dry granulation methods and utilize pharmaceutically acceptable diluents, binding agents, lubricants, disintegrants, surface modifying agents (including surfactants), suspending or stabilizing agents, including, but not limited to, magnesium stearate, stearic acid, sodium lauryl sulfate, talc, sugars, lactose, dextrin, starch, gelatin, cellulose, methyl cellulose, microcrystalline cellulose, sodium carboxymethyl cellulose, carboxymethylcellulose calcium, polyvinylpyrrolidine, alginic acid, acacia gum, xanthan gum, sodium citrate, complex silicates, calcium carbonate, glycine, sucrose, sorbitol, dicalcium phosphate, calcium sulfate, lactose, kaolin, mannitol, sodium chloride, low melting waxes, and ion exchange resins. Surface modifying agents include nonionic and anionic surface modifying agents. Representative examples of surface modifying agents include, but are not limited to, poloxamer 188, benzalkonium chloride, calcium stearate, cetostearl alcohol, cetomacrogol emulsifying wax, sorbitan esters, colloidal silicon dioxide, phosphates, sodium dodecylsulfate, magnesium aluminum silicate, and triethanolamine. Oral formulations described herein herein can utilize standard delay or time-release formulations to alter the absorption of the compound(s). An oral formulation can also consist of administering a compound disclosed herein in water or fruit juice, containing appropriate solubilizers or emulsifiers as needed. [0336] Liquid carriers can be used in preparing solutions, suspensions, emulsions, syrups, elixirs, and for inhaled delivery. A compound of the present teachings can be dissolved or suspended in a pharmaceutically acceptable liquid carrier such as water, an organic solvent, or a mixture of both, or a pharmaceutically acceptable oils or fats. The liquid carrier can contain other suitable pharmaceutical additives such as solubilizers, emulsifiers, buffers, preservatives, sweeteners, flavoring agents, suspending agents, thickening agents, colors, viscosity regulators, stabilizers, and osmo-regulators. Examples of liquid carriers for oral and parenteral administration include, but are not limited to, water (particularly containing additives as described herein, e.g., cellulose derivatives such as a sodium carboxymethyl cellulose solution), alcohols (including monohydric alcohols and polyhydric alcohols, e.g., glycols) and their derivatives, and oils (e.g., fractionated coconut oil and arachis oil). For parenteral administration, the carrier can be an oily ester such as ethyl oleate and isopropyl myristate. Sterile liquid carriers are used in sterile liquid form compositions for parenteral administration. The liquid carrier for pressurized compositions can be halogenated hydrocarbon or other pharmaceutically acceptable propellants. [0337] Liquid pharmaceutical compositions, which are sterile solutions or suspensions, can be utilized by, for example, intramuscular, intraperitoneal or subcutaneous injection. Sterile solutions can also be administered intravenously. Compositions for oral administration can be in either liquid or solid form. [0338] In embodiments, a pharmaceutical composition is in unit dosage form, for example, as tablets, capsules, powders, solutions, suspensions, emulsions, granules, or suppositories. In such form, the pharmaceutical composition can be sub-divided in unit dose(s) containing appropriate quantities of the compound. The unit dosage forms can be packaged compositions, for example, packeted powders, vials, ampoules, prefilled syringes or sachets containing liquids. Alternatively, the unit dosage form can be a capsule or tablet itself, or it can be the appropriate number of any such compositions in package form. Such unit dosage form can contain from about 1 mg/kg of compound to about 500 mg/kg of compound, and can be given in a single dose or in two or more doses. Such doses can be administered in any manner useful in directing the compound(s) to the recipient’s bloodstream, including orally, via implants, parenterally (including intravenous, intraperitoneal and subcutaneous injections), rectally, vaginally, and transdermally. [0339] When administered for the treatment or inhibition of a particular disease state or disorder, it is understood that an effective dosage can vary depending upon the particular compound utilized, the mode of administration, and severity of the condition being treated, as well as the various physical factors related to the individual being treated. In therapeutic applications, a compound of the present teachings can be provided to a patient already suffering from a disease in an amount sufficient to cure or at least partially ameliorate the symptoms of the disease and its complications. The dosage to be used in the treatment of a specific individual typically must be subjectively determined by the attending physician. The variables involved include the specific condition and its state as well as the size, age and response pattern of the patient.

[0340] In some cases it may be desirable to administer a compound directly to the airways of the patient, using devices such as, but not limited to, metered dose inhalers, breath-operated inhalers, multidose dry-powder inhalers, pumps, squeeze-actuated nebulized spray dispensers, aerosol dispensers, and aerosol nebulizers. For administration by intranasal or intrabronchial inhalation, the compounds of the present teachings can be formulated into a liquid composition, a solid composition, or an aerosol composition. The liquid composition can include, by way of illustration, one or more compounds of the present teachings dissolved, partially dissolved, or suspended in one or more pharmaceutically acceptable solvents and can be administered by, for example, a pump or a squeeze-actuated nebulized spray dispenser. The solvents can be, for example, isotonic saline or bacteriostatic water. The solid composition can be, by way of illustration, a powder preparation including one or more compounds of the present teachings intermixed with lactose or other inert powders that are acceptable for intrabronchial use, and can be administered by, for example, an aerosol dispenser or a device that breaks or punctures a capsule encasing the solid composition and delivers the solid composition for inhalation. The aerosol composition can include, by way of illustration, one or more compounds of the present teachings, propellants, surfactants, and co-solvents, and can be administered by, for example, a metered device. The propellants can be a chlorofluorocarbon (CFC), a hydrofluoroalkane (HFA), or other propellants that are physiologically and environmentally acceptable.]

[0341] Compounds described herein can be administered parenterally or intraperitoneally. Solutions or suspensions of these compounds or a pharmaceutically acceptable salts, hydrates, or esters thereof can be prepared in water suitably mixed with a surfactant such as hydroxylpropylcellulose. Dispersions can also be prepared in glycerol, liquid polyethylene glycols, and mixtures thereof in oils. Under ordinary conditions of storage and use, these preparations typically contain a preservative to inhibit the growth of microorganisms.

[0342] The pharmaceutical forms suitable for injection can include sterile aqueous solutions or dispersions and sterile powders for the extemporaneous preparation of sterile injectable solutions or dispersions. In some embodiments, the form can sterile and its viscosity permits it to flow through a syringe. The form preferably is stable under the conditions of manufacture and storage and can be preserved against the contaminating action of microorganisms such as bacteria and fungi. The carrier can be a solvent or dispersion medium containing, for example, water, ethanol, polyol (e.g., glycerol, propylene glycol and liquid polyethylene glycol), suitable mixtures thereof, and vegetable oils. [0343] Compounds described herein can be administered transdermally, i.e., administered across the surface of the body and the inner linings of bodily passages including epithelial and mucosal tissues. Such administration can be carried out using the compounds of the present teachings including pharmaceutically acceptable salts, hydrates, or esters thereof, in lotions, creams, foams, patches, suspensions, solutions, and suppositories (rectal and vaginal). [0344] Transdermal administration can be accomplished through the use of a transdermal patch containing a compound, such as a compound disclosed herein, and a carrier that can be inert to the compound, can be non-toxic to the skin, and can allow delivery of the compound for systemic absorption into the blood stream via the skin. The carrier can take any number of forms such as creams and ointments, pastes, gels, and occlusive devices. The creams and ointments can be viscous liquid or semisolid emulsions of either the oil-in-water or water-in- oil type. Pastes comprised of absorptive powders dispersed in petroleum or hydrophilic petroleum containing the compound can also be suitable. A variety of occlusive devices can be used to release the compound into the blood stream, such as a semi-permeable membrane covering a reservoir containing the compound with or without a carrier, or a matrix containing the compound. Other occlusive devices are known in the literature. [0345] Compounds described herein can be administered rectally or vaginally in the form of a conventional suppository. Suppository formulations can be made from traditional materials, including cocoa butter, with or without the addition of waxes to alter the suppository’s melting point, and glycerin. Water-soluble suppository bases, such as polyethylene glycols of various molecular weights, can also be used. [0346] Lipid formulations or nanocapsules can be used to introduce compounds of the present teachings into host cells either in vitro or in vivo. Lipid formulations and nanocapsules can be prepared by methods known in the art. [0347] To increase the effectiveness of compounds of the present teachings, it can be desirable to combine a compound with other agents effective in the treatment of the target disease. For example, other active compounds (i.e., other active ingredients or agents) effective in treating the target disease can be administered with compounds of the present teachings. The other agents can be administered at the same time or at different times than the compounds disclosed herein. Kits [0348] In some embodiments, provided herein are kits. The kits can include a compound or pharmaceutically acceptable form thereof, or pharmaceutical composition as described herein, in suitable packaging, and written material that can include instructions for use, discussion of clinical studies, listing of side effects, and the like. Kits are well suited for the delivery of solid oral dosage forms such as tablets or capsules. Such kits can also include information, such as scientific literature references, package insert materials, clinical trial results, and/or summaries of these and the like, which indicate or establish the activities and/or advantages of the pharmaceutical composition, and/or which describe dosing, administration, side effects, drug interactions, or other information useful to the health care provider. Such information can be based on the results of various studies, for example, studies using experimental animals involving in vivo models and studies based on human clinical trials. Therapeutic Methods [0349] Compounds of the present teachings can be useful for the treatment or inhibition of a pathological condition or disorder in a mammal, for example, a human subject. The present teachings accordingly provide methods of treating or inhibiting a pathological condition or disorder by providing to a mammal a compound of the present teachings (including its pharmaceutically acceptable salt) or a pharmaceutical composition that includes one or more compounds of the present teachings in combination or association with pharmaceutically acceptable carriers. Compounds of the present teachings can be administered alone or in combination with other therapeutically effective compounds or therapies for the treatment or inhibition of the pathological condition or disorder. [0350] Accordingly, compounds described herein can be particularly useful in treating diseases or disorders associated with defects in various components of signal transduction pathways and which are responsive to modulation (e.g., inhibition) of protein kinases. In embodiments, a compound described herein modulates (e.g., inhibitors) a protein kinase that is abl, Akt, bcr-abl, Blk, Brk, c-kit, c-met, c-src, CDK1, CDK2, CDK3, CDK4, CDK5, CDK6, CDK7, CDK8, CDK9, CDK10, cRaf1, CSK, EGFR, ErbB2, ErbB3, ErbB4, Erk, Pak, fes, FGFR1, FGFR2, FGFR3, FGFR4, FGFR5, Fgr, flt-1, Fps, Frk, Fyn, Hck, IGF-1R, INS-R, Jak, KDR, Lck, Lyn, MEK, p38, PDGFR, PIK, PKC, PYK2, ros, tie, tie2, TRK or Zap70. In embodiments, a compound described herein modulates (e.g., inhibits) a wild-type form of a kinase (e.g., EGFR). In embodiments, a compound described herein modulates (e.g., inhibits) a mutant form of a kinase (e.g., EGFR). [0351] In embodiments, a compound described herein, or any pharmaceutically acceptable form thereof such as a pharmaceutically acceptable salt thereof, modulates (e.g., inhibits) a kinase that is a tyrosine kinase (e.g., KIT, erb2, PDGFR, EGFR, VEGFR, src, or abl). [0352] In embodiments, a compound described herein, or any pharmaceutically acceptable form thereof such as a pharmaceutically acceptable salt thereof, modulates (e.g., inhibits) a kinase that is a serine/threonine kinase (e.g., mTorC1, mTorC2, ATM, ATR, DNA-PK, or Akt). [0353] In embodiments, a compound described herein, or any pharmaceutically acceptable form thereof such as a pharmaceutically acceptable salt thereof, can be used to treat or prevent a disease or disorder that is responsive to modulation (e.g., inhibition) of a protein kinase (e.g., abl, Akt, bcr-abl, Blk, Brk, c-kit, c-met, c-src, CDK1, CDK2, CDK3, CDK4, CDK5, CDK6, CDK7, CDK8, CDK9, CDK10, cRaf1, CSK, EGFR, ErbB2, ErbB3, ErbB4, Erk, Pak, fes, FGFR1, FGFR2, FGFR3, FGFR4, FGFR5, Fgr, flt-1, Fps, Frk, Fyn, Hck, IGF-1R, INS-R, Jak, KDR, Lck, Lyn, MEK, p38, PDGFR, PIK, PKC, PYK2, ros, tie, tie2, TRK or Zap70). [0354] In embodiments, a compound described herein, or any pharmaceutically acceptable form thereof such as a pharmaceutically acceptable salt thereof, can be used to treat or prevent a disease or disorder that is responsive to modulation (e.g., inhibition) of a tyrosine kinase (e.g., KIT, erb2, PDGFR, EGFR, VEGFR, src, or abl). [0355] In embodiments, a compound described herein, or any pharmaceutically acceptable form thereof such as a pharmaceutically acceptable salt thereof, can be used to treat or prevent a disease or disorder that is responsive to modulation (e.g., inhibition) of a serine/threonine kinase (e.g., mTorC1, mTorC2, ATM, ATR, DNA-PK, or Akt). [0356] In embodiments, a compound described herein modulates (e.g., inhibits) a wild-type form of a kinase (e.g., EGFR). In embodiments, a compound described herein modulates (e.g., inhibits) a mutant form of a kinase (e.g., EGFR). Selective Inhibition of Kinases [0357] The term "selective inhibition" or "selectively inhibit" as applied to a biologically active agent refers to the agent’s ability to selectively reduce the target signaling activity as compared to off-target signaling activity, via direct or interact interaction with the target. [0358] In some embodiments, a compound described herein, or any pharmaceutically acceptable salt thereof, selectively inhibits a kinase or kinase form over other kinases or other kinase forms. In embodiments, a compound selectively inhibits a mutant kinase form over the wild-type of the same kinase. [0359] In embodiments, a compound described herein, or any pharmaceutically acceptable salt thereof, selectively inhibits a kinase (e.g., EGFR) over other kinases. [0360] In embodiments, a compound described herein, or any pharmaceutically acceptable salt thereof, selectively inhibits a kinase form (e.g., mutant EGFR) over other kinase forms (e.g., wild-type EGFR). [0361] By way of non-limiting example, the ratio of selectivity can be greater than a factor of about 10, greater than a factor of about 20, greater than a factor of about 30, greater than a factor of about 40, greater than a factor of about 50, greater than a factor of about 60, greater than a factor of about 70, greater than a factor of about 80, greater than a factor of about 100, greater than a factor of about 120, or greater than a factor of about 150, where selectivity can be measured by in vitro assays known in the art. Non-limiting examples of assays to measure selectivity include enzymatic assays, cellular proliferation assays, and EGFR phosphorylation assays. In one embodiment, selectivity can be determined by cellular proliferation assays. In another embodiment, selectivity can be determined by EGFR phosphorylation assays. In some embodiments, the mutant EGFR inhibitory activity of a compound as disclosed herein can be less than about 1000 nM, less than about 100 nM, less than about 50 nM, less than about 30 nM, or less than about 10 nM. [0362] In embodiments, the IC50 of a kinase inhibitor compound can be less than about 100 nM, less than about 50 nM, less than about 10 nM, less than about 1 nM, less than about 0.5 nM, or less than about 1 pM. [0363] Determination of IC ₅₀ values can be performed according to methods known in the art. [0364] In embodiments, a compound described herein, or any pharmaceutically acceptable form thereof such as a pharmaceutically acceptable salt thereof, can be used to treat or prevent a disease or disorder that is cancer, an inflammatory disorder, a metabolic disorder, vascular disease, or neuronal disease. [0365] Compounds described herein, or any pharmaceutically acceptable form thereof, or any pharmaceutical composition thereof, can be useful for treating diseases and disorders associated with abnormal cell proliferation.

[0366] In embodiments, a compound described herein, or a pharmaceutically acceptable form thereof (e.g., a pharmaceutically acceptable salt thereof), or a pharmaceutical composition thereof, can be used to treat cancer.

Cancer

[0367] The compositions and methods provided herein can potentially be useful for the treatment of cancer including tumors such as astrocytic, breast, cervical, colorectal, endometrial, esophageal, gastric, head and neck, hepatocellular, laryngeal, lung, oral, ovarian, prostate and thyroid carcinomas and sarcomas.

[0368] In embodiments, a cancer is a cardiac cancer such as sarcoma (angiosarcoma, fibrosarcoma, rhabdomyosarcoma, liposarcoma), myxoma, rhabdomyoma, fibroma, lipoma or teratoma.

[0369] In embodiments, a cancer is a lung cancer such as bronchogenic carcinoma (squamous cell, undifferentiated small cell, undifferentiated large cell, adenocarcinoma), alveolar (bronchiolar) carcinoma, bronchial adenoma, sarcoma, lymphoma, chondromatous hamartoma, or mesothelioma.

[0370] In embodiments, a cancer is a gastrointestinal cancer such as: esophagus (squamous cell carcinoma, adenocarcinoma, leiomyosarcoma, lymphoma), stomach (carcinoma, lymphoma, leiomyosarcoma), pancreas (ductal adenocarcinoma, insulinoma, glucagonoma, gastrinoma, carcinoid tumors, vipoma), small bowel (adenocarcinoma, lymphoma, carcinoid tumors, Kaposi's sarcoma, leiomyoma, hemangioma, lipoma, neurofibroma, fibroma), large bowel (adenocarcinoma, tubular adenoma, villous adenoma, hamartoma, leiomyoma).

[0371] In embodiments, a cancer is a cancer of the genitourinary tract such as: kidney (adenocarcinoma, Wilm's tumor (nephroblastoma), lymphoma, leukemia), bladder and urethra (squamous cell carcinoma, transitional cell carcinoma, adenocarcinoma), prostate (adenocarcinoma, sarcoma), testis (seminoma, teratoma, embryonal carcinoma, teratocarcinoma, choriocarcinoma, sarcoma, interstitial cell carcinoma, fibroma, fibroadenoma, adenomatoid tumors, lipoma). [0372] In embodiments a cancer is a liver cancer such as hepatoma (hepatocellular carcinoma), cholangiocarcinoma, hepatoblastoma, angiosarcoma, hepatocellular adenoma, hemangioma.

[0373] In embodiments, a cancer is a bone cancer such as: osteogenic sarcoma (osteosarcoma), fibrosarcoma, malignant fibrous histiocytoma, chondrosarcoma, Ewing's sarcoma, malignant lymphoma (reticulum cell sarcoma), multiple myeloma, malignant giant cell tumor chordoma, osteochronfroma (osteocartilaginous exostoses), benign chondroma, chondroblastoma, chondromyxofibroma, osteoid osteoma and giant cell tumors.

[0374] In embodiments a cancer is a cancer of the central nervous system (CNS) such as: skull (osteoma, hemangioma, granuloma, xanthoma, osteitis deformans), meninges (meningioma, meningiosarcoma, gliomatosis), brain (astrocytoma, medulloblastoma, glioma, ependymoma, germinoma (pinealoma), glioblastoma multiform, oligodendroglioma, schwannoma, retinoblastoma, congenital tumors), spinal cord neurofibroma, meningioma, glioma, sarcoma).

[0375] In embodiments, a cancer is a gynecological cancer such as: uterus (endometrial carcinoma), cervix (cervical carcinoma, pre -tumor cervical dysplasia), ovaries (ovarian carcinoma (serous cystadenocarcinoma, mucinous cystadenocarcinoma, unclassified carcinoma), granulosa-thecal cell tumors, Sertoli-Leydig cell tumors, dysgerminoma, malignant teratoma), vulva (squamous cell carcinoma, intraepithelial carcinoma, adenocarcinoma, fibrosarcoma, melanoma), vagina (clear cell carcinoma, squamous cell carcinoma, botryoid sarcoma (embryonal rhabdomyosarcoma), fallopian tubes (carcinoma).

[0376] In embodiments, a cancer is a hematological cancer such as: blood (myeloid leukemia (acute and chronic), acute lymphoblastic leukemia, chronic lymphocytic leukemia, myeloproliferative diseases, multiple myeloma, myelodysplasia syndrome), Hodgkin's disease, non-Hodgkin's lymphoma (malignant lymphoma).

[0377] In embodiments, a cancer is a skin cancer such as: malignant melanoma, basal cell carcinoma, squamous cell carcinoma, Kaposi's sarcoma, moles dysplastic nevi, lipoma, angioma, dermatofibroma, keloids, psoriasis.

[0378] In embodiments, a cancer is a cancer of the adrenal glands such as neuroblastoma.

Thus, the term "cancerous cell" as provided herein, includes a cell afflicted by any one of or related to the above identified conditions. [0379] In embodiments, a cancer is an EGFR-driven cancer (e.g., as described herein). In embodiments, an EGFR-driven cancer is non-small cell lung cancer (NSCLC), squamous cell carcinoma, adenocarcinoma, adenocarcinoma, bronchioloalveolar carcinoma (BAC), BAC with focal invasion, adenocarcinoma with BAC features, and large cell carcinoma; neural tumors, such as glioblastomas; pancreatic cancer; head and neck cancers (e.g., squamous cell carcinoma); breast cancer; colorectal cancer; epithelial cancer, including squamous cell carcinoma; ovarian cancer; prostate cancer; or adenocarcinomas.

[0380] In embodiments, a cancer is an EGFR mutant cancer (e.g., as described herein). In embodiments, an EGFR mutant cancer is non-small cell lung cancer (NSCLC), squamous cell carcinoma, adenocarcinoma, adenocarcinoma, bronchioloalveolar carcinoma (BAC), BAC with focal invasion, adenocarcinoma with BAC features, and large cell carcinoma; neural tumors, such as glioblastomas; pancreatic cancer; head and neck cancers (e.g., squamous cell carcinoma); breast cancer; colorectal cancer; epithelial cancer, including squamous cell carcinoma; ovarian cancer; prostate cancer; or adenocarcinomas.

[0381] In one embodiment, the compositions and methods provided herein are useful for the treatment of lung cancer and pancreatic cancer, most specifically, non-small cell lung cancer (NSCLC).

[0382] In embodiments, a cancer is refractory to TKI therapies (e.g., erlotinib, gefitinib, dacomitinib, afatinib, osimertinib).

Lung Cancer

[0383] In embodiments, a cancer is a lung cancer.

[0384] Lung cancer is the most common cause of cancer mortality globally and the second most common cancer in both men and women. About 14% of all new cancers are lung cancers. In the United States (US), there are projected to be 222,500 new cases of lung cancer (116,990 in men and 105,510 in women) and 155,870 deaths from lung cancer (84,590 in men and 71,280 in women) in 2017.

[0385] The two major forms of lung cancer are non-small cell lung cancer (NSCLC) and small cell lung cancer. NSCLC is a heterogeneous disease that consists of adenocarcinoma, large-cell carcinoma, and squamous cell carcinoma (sqNSCLC), and comprises approximately 80% to 85% of all lung cancers. Squamous cell carcinoma of the lung accounts for 20% to 30% of NSCLC. Despite advances in early detection and standard treatment, NSCLC is often diagnosed at an advanced stage, has poor prognosis, and is the leading cause of cancer deaths worldwide. [0386] Platinum-based doublet therapy, maintenance chemotherapy, and anti-angiogenic agents in combination with chemotherapy have contributed to improved patient outcomes in advanced NSCLC. [0387] In embodiments, an advanced lung cancer is stage III cancer or stage IV cancer. In embodiments, an advanced lung cancer is stage III cancer. In embodiments, an advanced lung cancer is stage IV cancer. In embodiments, an advanced lung cancer is locally advanced. In embodiments, an advanced lung cancer is metastatic. [0388] In embodiments, a lung cancer is small cell lung cancer (SCLC). [0389] In embodiments, a lung cancer is non-small cell lung cancer (NSCLC) such as adenocarcinoma, large-cell carcinoma, or squamous cell carcinoma (sqNSCLC). In embodiments, a NSCLC is lung adenocarcinoma. In embodiments, a NSCLC is large cell carcinoma of the lung. In embodiments, a NSCLC is squamous cell carcinoma of the lung (sqNSCLC). [0390] In embodiments, a lung cancer (e.g., NSCLC) is an EGFR-mutant lung cancer (e.g., EGFR-mutant NSCLC). In embodiments, a cancer is NSCLC (e.g., advanced NSCLC) with an identified EGFR mutation. EGFR Driven and EGFR Mutant Cancers [0391] The invention features compounds which can be useful for treating patients who have an EGFR-driven cancer, including cancers which are, or have become, refractory to erlotinib, gefitinib, dacomitinib, afatinib, osimertinib , or cancers which bear an EGFR mutation identified herein, by administering a compound of formula (I) to a subject. [0392] EGFR-driven cancers which can be treated using the compositions and method of the invention include, for example, EGFR mutants including one or more deletions, substitutions, or additions in the amino acid or nucleotide sequences of EGFR, or fragments thereof. [0393] An EGFR-driven cancer may result from an EGFR fusion. For example, the N-terminal of EGFR can be linked to various fusion partners such as RAD51. Cancers (e.g., lung cancers) characterized by an EGFR-fusion (e.g., an EGFR-RAD51 fusion) may be particularly suitable for therapy using any compound described herein, or any pharmaceutically acceptable form (e.g., a pharmaceutically acceptable salt) thereof. [0394] Mutations in EGFR can occur in any part of the EGFR sequence. Generally, EGFR mutants arise from mutations in the kinase domain (i.e., exons 18-24 in the EGFR sequence) or in the extracellular domain (i.e., exons 2-16 in the EGFR sequence). [0395] A mutation in EGFR can be an activating mutation, which lead to a ligand- independent activation of TK activity. A mutation in EGFR can also be a resistance mutation, which can confer resistance to TKI therapies such as resistance to one or more of erlotinib, gefitinib, dacomitinib, afatinib, or osimertinib. [0396] For example, mutations typically occur in the kinase domain, including one or more of a point mutation in exon 18 (e.g., L688P, V689M, P694L/S, N700D, L703V, E709K/Q/A/G/V, I715S, L718P, G719C/A/S/R, or S720P/F), a deletion in exon 19 that may or may not include an insertion (e.g., delG719, delE746_E749, delE746_A750, delE746_A750insRP, delE746_A750insQP, delE746_T751, delE746_T751insA/I/V, delE746_T751insVA, delE746_S752, delE746_S752insA/V/D, delE746_P53insLS, delL747_E749, delL747_A750, delL747_A750insP, delL747_T751, delL747_T751insP/S/Q, delL747_T751insPI, delL747_S752, delL747_S752insQ, delL747_P753, delL747_P753insS/Q, delL747_L754insSR, delE749_A750, delE749_A750insRP, delE749_T751, delT751_I759, delT751_I759insS/N, or delS752_I759), a duplication in exon 19 (e.g., K739_I44dupKIPVAI), a point mutation in exon 19 (e.g., L730F, W731Stop, P733L, G735S, V742A, E746V/K, A750P, T751I, S752Y, P753S, A754P, or D761Y), an in-frame insertion in exon 20 (e.g., D761_E762insEAFQ, A767_S768insTLA, V769_D770insY, V769_D770insCV, V769_D770insASV, D770_N771insD/G, D770_N771insNPG, D770_N771insSVQ, P772_H773insN/V, P772_H773insYNP, or V774_C775insHV), a deletion in exon 20 that may or may not include an insertion (e.g., delM766_A767, delM766_A767insAI, delA767_V769, delD770, or delP772_H773insNP), a duplication in exon 20 (e.g., S768_D770dupSVD, A767_V769dupASV, or H773dupH), a point mutation in exon 20 (e.g., D761N, A763V, V765A/M, S768I, V769L/M, S768I, P772R, N771T, H773R/Y/L, V774M, R776G/H/C, G779S/F, T783A, T784F, L792P, L798H/F, T790M, R803W, K806E, or L814P), or a point mutation in exon 21 (e.g., G810S, N826S, L833V, H835L, L838V, A839T, K846R, T847I, H850N, V851I/A, I853T, L858M/R, A859T, L861Q/R, G863D, A864T, E866K, or G873E). [0397] In lung cancer, activation mutants are typical. [0398] In embodiments, a mutation is a resistance mutation. In particular, drug resistance in 50% of lung cancers arises from the T790M point mutation. Other exemplary resistance mutation include point mutations such as: C797X (e.g., C797S, C797G, or C797N); G796X (e.g., G796R, G796S, or G796D); L792X (e.g. L792H, L792F, L792R, or L792Y); G724S; L718X (e.g., L718P, L718Q, or L718V); S768I; or G719A. [0399] In glioblastoma, mutations typically, but not exclusively, occur in the extracellular domain, including EGFR variant I (EGFRvI) lacking the extracellular domain and resembling the v-erbB oncoprotein; EGFRvII lacking 83 amino acids from domain IV; and EGFRvIII lacking amino acids 30-297 from domains I and II, which is the most common amplification and is reported in 30-50% of glioblastomas and 5% of squamous cell carcinoma. Other mutations for glioblastoma include one or more of point mutations in exon 2 (e.g., D46N or G63R), exon 3 (e.g., R108K in domain I), exon 7 (e.g., T263P or A289D/T/V in domain II), exon 8 (e.g., R324L or E330K), exon 15 (e.g., P596L or G598V in domain IV), or exon 21 (L861Q in the kinase domain). [0400] EGFR mutants also include those with a combination of two or more mutations, as described herein. Exemplary combinations include S768I and G719A; S768I and V769L; H773R and W731Stop; R776G and L858R; R776H and L861Q; T790M and L858R; T790M and delE746_A750; R803W and delE746_T751insVA; delL747_E749 and A750P; delL747_S752 and E746V; delL747_S752 and P753S; P772_H773insYNP and H773Y; P772_H773insNP and H773Y; and D770_N771insG and N771T. Other exemplary combinations include any including T790M (e.g., T790M and L858R or T790M and delE746_A750. [0401] EGFR mutants can be either activation mutants or resistant mutants. Activation mutants include those with substitutions that increase drug sensitivity (e.g., G719C/S/A, delE746_A750, or L858R). Resistant mutants include those with substitutions that increase drug resistance (e.g., T790M or any combination including T790M). [0402] In embodiments, an EGFR mutation is a deletion in exon19 (del19). In embodiments, an EGFR mutation is a T790M mutation. In embodiments, an EGFR mutation is a L858R mutation. In embodiments, an EGFR mutation is a C797S mutation. In embodiments, an EGFR-driven cancer (e.g., non-small cell lung cancer) is characterized by at least one of these mutations. In embodiments, an EGFR-driven cancer (e.g., non-small cell lung cancer) is characterized by at least two of these mutations. In embodiments, an EGFR-driven cancer (e.g., non-small cell lung cancer) is characterized by at least three of these mutations. [0403] EGFR-driven cancers include those having any mutant described herein. For example, EGFRvIII is commonly found in glioblastoma and has also been reported in breast, ovarian, prostate, and lung carcinomas. Exemplary EGFR-driven cancers: glioblastoma, lung cancer (e.g., squamous cell carcinoma, non-small cell lung cancer, adenocarcinoma, bronchioloalveolar carcinoma (BAC), BAC with focal invasion, adenocarcinoma with BAC features, and large cell carcinoma), pancreatic cancer, head and neck cancers (e.g., squamous cell carcinoma), breast cancer, colorectal cancer, epithelial cancer (e.g., squamous cell carcinoma), ovarian cancer, and prostate cancer. [0404] In particular, the invention described herein would benefit patient populations having higher risk for TKI-resistant mutations. About 8,000 to 16,000 new cases per year can be estimated based on: incidence of non-small cell lung cancer (about 160,000 new cases in the U.S.), the response to erlotinib in the general population (about 10%, resulting in a sensitive population of 16,000), the presence of activation mutations (10-20% in white and 30-40% in Asian population, resulting in a sensitive population of 16,000-32,000), acquisition of secondary resistance (most if not all patients, resulting in a sensitive population of 16,000- 32,000), and percentage of patients carrying the T790M point mutations (about 50%, resulting in a sensitive population of 8,000-16,000). Patients having TKI-resistant mutations include those patients having cancers resistant to one or more of erlotinib, gefitinib, dacomitinib, afatinib, osimertinib, CL-387,785, BIBW 2992 (CAS Reg. No.439081-18-2), CI-1033, neratinib (HKI-272), MP-412 (AV-412), PF-299804, AEE78, and XL64. [0405] In particular, the inventions relate to treatment of EGFR-driven cancers having the T790M point mutation. Generally, irreversible inhibitors (e.g., CI-1033, neratinib (HKI-272), and PF-299804) are less potent in cell lines having the T790M mutation and do not inhibit T790M at clinically achievable concentrations. Since the ATP Km of T790M and WT are similar, concentrations that inhibit the mutant will inhibit the WT and result in gastrointestinal and cutaneous events. [0406] An EGFR mutant also includes other amino acid and nucleotide sequences of EGFR with one or more deletions, substitutions, or additions, such as point mutations, that retain or increase tyrosine kinase or phosphorylation activity. Where the mutant is a protein or polypeptide, preferable substitutions are conservative substitutions, which are substitutions between amino acids similar in properties such as structural, electric, polar, or hydrophobic properties. For example, the substitution can be conducted between basic amino acids (e.g., Lys, Arg, and His), or between acidic amino acids (e.g., Asp and Glu), or between amino acids having non-charged polar side chains (e.g., Gly, Asn, Gln, Ser, Thr, Tyr, and Cys), or between amino acids having hydrophobic side chains (e.g., Ala, Val, Leu, Ile, Pro, Phe, and Met), or between amino acids having branched side chains (e.g., Thr, Val, Leu, and Ile), or between amino acids having aromatic side chains (e.g., Tyr, Trp, Phe, and His). [0407] Where the mutant is a nucleic acid, the DNA encoding an EGFR mutant protein may comprise a nucleotide sequence capable of hybridizing to a complement sequence of the nucleotide sequence encoding an EGFR mutant, as defined herein, under stringent conditions. As used herein, the stringent conditions include low, medium or high stringent conditions. An example of the stringent conditions includes hybridization at approximately 42-55°C in approximately 2-6 x SSC, followed by wash at approximately 50-65°C in approximately 0.1-1 x SSC containing approximately 0.1-0.2% SDS, where 1 x SSC is a solution containing 0.15 M NaCl and 0.015 M Na citrate, pH 7.0. Wash can be performed once or more. In general, stringent conditions may be set at a temperature approximately 5°C lower than a melting temperature (Tm) of a specific nucleotide sequence at defined ionic strength and pH. [0408] The amino acid and nucleotide sequences of EGFR and DNAs encoding them are available from known databases such as NCBI GenBank (USA), EMBL (Europe), etc. For example, GenBank accession numbers for EGFR [Homo sapiens] include MIM131550, AAI28420, NM_005228, NP_005219.2, and GeneID: 1956. EGFR-Selective Inhibition [0409] In some embodiments, a compound described herein, or any pharmaceutically acceptable salt thereof, selectively inhibits EGFR (including any mutant EGFR described herein) over other kinases. [0410] In some embodiments, a compound described herein, or any pharmaceutically acceptable salt thereof, selectively inhibits mutant EGFR (e.g., any mutant EGFR described herein) over wild-type EGFR. In embodiments, a compound described herein selectively inhibits EGFR characterized by a mutation that is: a deletion in exon19 (del19), a T790M mutation, a L858R mutation, and/or a C797S mutation, or any combination thereof. Such inhibitors can be effective in ameliorating diseases and disorders associated with mutant EGFR activity. [0411] By way of non-limiting example, the ratio of selectivity can be greater than a factor of about 10, greater than a factor of about 20, greater than a factor of about 30, greater than a factor of about 40, greater than a factor of about 50, greater than a factor of about 60, greater than a factor of about 70, greater than a factor of about 80, greater than a factor of about 100, greater than a factor of about 120, or greater than a factor of about 150, where selectivity can be measured by in vitro assays known in the art. Non-limiting examples of assays to measure selectivity include enzymatic assays, cellular proliferation assays, and EGFR phosphorylation assays. In one embodiment, selectivity can be determined by cellular proliferation assays. In another embodiment, selectivity can be determined by EGFR phosphorylation assays. In some embodiments, the mutant EGFR inhibitory activity of a compound as disclosed herein can be less than about 1000 nM, less than about 100 nM, less than about 50 nM, less than about 30 nM, or less than about 10 nM. [0412] In embodiments, the IC50 of a subject compound for mutant EGFR inhibition can be less than about 100 nM, less than about 50 nM, less than about 10 nM, less than about 1 nM, less than about 0.5 nM, or less than about 1 pM. Characterization of EGFR-driven Cancers [0413] The compositions and methods of the invention can be used to treat subjects having an EGFR-driven cancer (i.e., cancers characterized by EGFR mutant expression or overexpression). EGFR mutant expression or overexpression can be determined in a diagnostic or prognostic assay by evaluating levels of EGFR mutants in biological sample, or secreted by the cell (e.g., via an immunohistochemistry assay using anti-EGFR antibodies or anti-p-EGFR antibodies; FACS analysis, etc.). Alternatively, or additionally, one can measure levels of EGFR mutant-encoding nucleic acid or mRNA in the cell, e.g., via fluorescent in situ hybridization using a nucleic acid based probe corresponding to an EGFR mutant-encoding nucleic acid or the complement thereof; (FISH; see WO98/45479, published October, 1998), Southern blotting, Northern blotting, or polymerase chain reaction (PCR) techniques, such as real time quantitative PCR (RT-PCR). One can also study EGFR mutant expression by measuring shed antigen in a biological sample, such as serum, e.g., using antibody-based assays (see also, e.g., U.S. Patent No.4,933,294, issued June 12, 1990; WO91/05264, published April 18, 1991; U.S. Patent 5,401,638, issued March 28, 1995; and Sias et al., J. Immunol. Methods 132:73 (1990)). Aside from the above assays, various in vivo assays are available to the skilled practitioner. For example, one can expose cells within the body of the mammal to an antibody which is optionally labeled with a detectable label, e.g., a radioactive isotope, and binding of the antibody to cells in the mammal can be evaluated, e.g., by external scanning for radioactivity or by analyzing a biopsy taken from a mammal previously exposed to the antibody. [0414] Examples of biological properties that can be measured in isolated cells include mRNA expression, protein expression, and DNA quantification. Additionally, the DNA of cells isolated by the methods of the invention can be sequenced, or certain sequence characteristics (e.g., polymorphisms and chromosomal abnormalities) can be identified using standard techniques, e.g., FISH or PCR. The chemical components of cells, and other analytes, may also be assayed after isolation. Cells may also be assayed without lysis, e.g., using extracellular or intracellular stains or by other observation, e.g., morphology or growth characteristics in various media. [0415] While any hybridization technique can be used to detect the gene rearrangements, one preferred technique is fluorescent in situ hybridization (FISH). FISH is a cytogenetic technique which can be used to detect and localize the presence or absence of specific DNA or RNA sequences on chromosomes. FISH incorporates the use of fluorescently labeled nucleic acid probes which bind only to those parts of the chromosome with which they show a high degree of sequence similarity. Fluorescence microscopy can be used to find out where the fluorescent probe bound to the chromosome. The basic steps of FISH are outlined below. Exemplary FISH probes include Vysis EGFR SpectrumOrange/ CEP SpectrumGreen Probe (Abbott, Downers Grove, IL), which hybridizes to band 7p12; and ZytoLight SPEC EGFR/CEN 7 Dual Color Probe (ZytoVision), which hybridizes to the alpha-satellite sequences of the centromere of chromosome 7. [0416] For FISH, a probe is constructed that is long enough to hybridize specifically to its target (and not to similar sequences in the genome), but not too large to impede the hybridization process. Probes are generally labeled with fluorophores, with targets for antibodies, with biotin, or any combination thereof. This can be done in various ways, for example using random priming, nick translation, and PCR using tagged nucleotides. [0417] Generally, a sample or aliquot of a population of cells is used for FISH analysis. For example, in one method of preparation, cells are trypsinized to disperse into single cells, cytospun onto glass slides, and then fixed with paraformaldehyde before storing in 70% ethanol. For preparation of the chromosomes for FISH, the chromosomes are firmly attached to a substrate, usually glass. After preparation, the probe is applied to the chromosome RNA and starts to hybridize. In several wash steps, all unhybridized or partially hybridized probes are washed away. If signal amplification is necessary to exceed the detection threshold of the microscope (which depends on many factors such as probe labeling efficiency, the kind of probe, and the fluorescent dye), fluorescent tagged antibodies or strepavidin are bound to the tag molecules, thus amplifying the fluorescence. [0418] An epifluorescence microscope can be used for observation of the hybridized sequences. The white light of the source lamp is filtered so that only the relevant wavelengths for excitation of the fluorescent molecules arrive onto the sample. Emission of the fluorochromes happens, in general, at larger wavelengths, which allows one to distinguish between excitation and emission light by mean of another optical filter. With a more sophisticated filter set, it is possible to distinguish between several excitation and emission bands, and thus between several fluorochromes, which allows observation of many different probes on the same strand. [0419] Depending on the probes used, FISH can have resolution ranging from huge chromosomes or tiny (~100 kilobase) sequences. The probes can be quantified simply by counting dots or comparing color. [0420] Allele-specific quantitative real time-PCR may also be used to identify a nucleic acid encoding a mutant EGFR protein (see, for e.g., Diagnostic Innovations DxS BCR-ABL T3151 Mutation Test Kit, and Singer et al., Methods in Molec. Biol.181:145 (2001)). This technique utilizes Taq DNA polymerase, which is extremely effective at distinguishing between a match and a mismatch at the 3’-end of the primer (when the 3’-base is mismatched, no efficient amplification occurs). Using this technique, the 3’-end of the primer may be designed to specifically hybridize to a nucleic acid sequence that corresponds to a codon that encodes a mutant amino acid in an EGFR mutant, as described herein. In this way, the specific mutated sequences can be selectively amplified in a patient sample. This technique further utilizes a Scorpion probe molecule, which is a bifunctional molecule containing a PCR primer, a fluorophore, and a quencher. The fluorophore in the probe interacts with a quencher, which reduces fluorescence. During a PCR reaction, when the Scorpion probe binds to the amplicon, the fluorophore and quencher in the Scorpion probe become separated, which leads to an increase in fluorescence from the reaction tube. Any of the primers described herein may be used in allele-specific quantitative real time PCR. [0421] A biological sample can be analyzed to detect a mutation in an EGFR gene, or expression levels of an EGFR gene, by methods that are known in the art. For example, methods such as direct nucleic acid sequencing, altered hybridization, aberrant electrophoretic gel migration, binding or cleavage mediated by mismatch binding proteins, single-strand conformational polymorphism (SSCP) analysis, or restriction fragment length polymorphism (RFLP) analysis of PCR products derived from a patient sample can be used to detect a mutation in an EGFR gene; ELISA can be used to measure levels of EGFR polypeptide; and PCR can be used to measure the level of an EGFR nucleic acid molecule. [0422] Any of these techniques may be used to facilitate detection of a mutation in a candidate gene, and each is well known in the art; examples of particular techniques are described, without limitation, in Orita et al. (Proc. Natl. Acad. Sci. USA 86:2766 (1989)) and Sheffield et al. (Proc. Natl. Acad. Sci. USA 86:232 (1989)). Furthermore, expression of the candidate gene in a biological sample (e.g., a biopsy) may be monitored by standard Northern blot analysis or may be aided by PCR (see, e.g., Ausubel et al., Current Protocols in Molecular Biology, John Wiley & Sons, New York, NY (1995); PCR Technology: Principles and Applications for DNA Amplification, H.A. Ehrlich, Ed., Stockton Press, NY; Yap et al., Nucl. Acids. Res.19:4294 (1991)). [0423] One skilled in the art may identify in a nucleic acid or protein sequence a residue (e.g., amino acid or nucleotide) or codon that corresponds to a residue or codon in wild-type EGFR or EGFR mutants using a number of sequence alignment software programs (e.g., NCBI BLAST website). Such software programs may allow for gaps in the alignment of the compared sequences. Using such software, one skilled in the art may identify a nucleotide, amino acid, or amino acid that corresponding to a specific nucleotide, amino acid, or codon in wild-type EGFR or EGFR mutants. [0424] Levels of EGFR expression (e.g., DNA, mRNA, or protein) in a biological sample can be determined by using any of a number of standard techniques that are well known in the art or described herein. Exemplary biological samples include plasma, blood, sputum, pleural effusion, bronchoalveolar lavage, or biopsy, such as a lung biopsy and lymph node biopsy. For example, EGFR expression in a biological sample (e.g., a blood or tissue sample) from a patient can be monitored by standard northern blot analysis or by quantitative PCR (see, e.g., Ausubel et al., supra; PCR Technology: Principles and Applications for DNA Amplification, H.A. Ehrlich, Ed., Stockton Press, NY; Yap et al., Nucl. Acids. Res.19:4294 (1991)). Combination Therapies [0425] In some embodiments, provided herein are methods for combination therapies in which an agent known to modulate other pathways, or other components of the same pathway, or even overlapping sets of target enzymes are used in combination with a compound as provided herein, or a pharmaceutically acceptable form (e.g., pharmaceutically acceptable salts, hydrates, solvates, isomers, prodrugs, and isotopically labeled derivatives) thereof. In one aspect, such therapy includes, but is not limited to, the combination of the subject compound with chemotherapeutic agents, therapeutic antibodies, and radiation treatment, to provide a synergistic or additive therapeutic effect. [0426] When administered as a combination, the therapeutic agents can be formulated as separate compositions that are administered at the same time or sequentially at different times, or the therapeutic agents can be given as a single composition. The phrase “combination therapy", in referring to the use of a disclosed compound together with another pharmaceutical agent, means the coadministration of each agent in a substantially simultaneous manner as well as the administration of each agent in a sequential manner, in either case, in a regimen that will provide beneficial effects of the drug combination. Coadministration includes, inter alia, the simultaneous delivery, e.g., in a single tablet, capsule, injection or other dosage form having a fixed ratio of these active agents, as well as the simultaneous delivery in multiple, separate dosage forms for each agent respectively. Thus, the administration of disclosed compounds can be in conjunction with additional therapies known to those skilled in the art in the prevention or treatment of cancer, such as radiation therapy or cytostatic agents, cytotoxic agents, other anti-cancer agents and other drugs to amerliorate symptoms of the cancer or side effects of any of the drugs. [0427] In some embodiments, treatment can be provided in combination with one or more other cancer therapies, include surgery, radiotherapy (e.g., gamma-radiation, neutron beam radiotherapy, electron beam radiotherapy, proton therapy, brachytherapy, and systemic radioactive isotopes, etc.), endocrine therapy, biologic response modifiers (e.g., interferons, interleukins, and tumor necrosis factor (TNF)), hyperthermia, cryotherapy, agents to attenuate any adverse effects (e.g., antiemetics), and other cancer chemotherapeutic drugs. The other agent(s) can be administered using a formulation, route of administration and dosing schedule the same or different from that used with the compounds provided herein.

[0428] In embodiments, combination therapy comprises administration of a compound described herein, or any pharmaceutically acceptable form thereof (e.g., any pharmaceutically acceptable salt thereof), or a pharmaceutical composition thereof, in combination with anticancer drugs (e.g., antiproliferative agents, anti-angiogenic agents and other chemotherapeutic agents).

[0429] In embodiments, combination therapy comprises administration of a compound described herein, or any pharmaceutically acceptable form thereof (e.g., any pharmaceutically acceptable salt thereof), or a pharmaceutical composition thereof, in combination with an amount of an anti-cancer agent (e.g., a chemotherapeutic agent).

[0430] From the foregoing description, one skilled in the art can easily ascertain the essential characteristics of this invention, and without departing from the spirit and scope thereof, can make various changes and modifications of the invention to adapt it to various usages and conditions.

[0431] All references, patents or applications, U.S. or foreign, cited in the application are hereby incorporated by reference as if written herein in their entireties. Where any inconsistencies arise, material literally disclosed herein controls.