To provide a new cytokine-like protein and a DNA encoding the protein, and to provide a method for producing the protein, a method for screening a compound bindable to the protein, and pharmaceutical applications of the compound.

A full-length cDNA corresponding to an EST (AA418955), which does not show any homology to other proteins but has a weak homology to G-CSF, has been successfully isolated by synthesizing primers based on the EST sequence and effecting PCR-cloning from a human fetal spleen library. Sequencing of the thus-isolated cDNA and analysis of its structure has revealed that the thus isolated cDNA has typical characteristics of a factor belonging to the IL-6/G-CSF/MGF family. It has also been found that the culture supernatant of the isolated gene-transfected CHO cells shows a proliferation supporting activity towards bone marrow cells in the coexistence of kit ligand.