To provide compositions comprising a glycoprotein having an Fc region.

The composition comprises a mature core carbohydrate structure lacking fucose wherein 51-100% of the glycoprotein in the composition is attached to the Fc region of the glycoprotein. The Fc region contains an amino acid sequence that differs from a native sequence of a human IgG Fc region. The composition comprises a glycoprotein having a human IgG Fc region, wherein the glycoprotein binds the FcγRIII with better affinity, or mediates antibody-dependent cell-mediated cytotoxicity (ADCC) more effectively, than the glycoprotein with a mature core carbohydrate structure including fucose attached to the Fc region of the glycoprotein. The preferred glycoprotein is an antibody or an immunoadhesin.