Activin Receptor Type II B inhibitors including extracellular domain of delta-like 1 homolog

The present invention relates to a liquid activin receptor type 2B inhibitor comprises the extracellular domain of the soluble domain DLK1 (delta-like 1 homolog). The present invention more specifically is, liquid activin receptor type comprising a variant (mutant) or fragment of the variants of the outer of the outer of the outer of DLK1 cell-accepting domain, DLK1 cell-accepting domain fragment, DLK1 cell soluble domains, as an active ingredient 2B relates to the like (activin receptor type II B, ACVR2B) and inhibiting binding of the ligand composition having the ACVR2B receptor and pharmaceutical compositions for preventing or treating disease comprising the same. Bars by combining compositions of the present invention are liquid activin competitively to ligand with the liquid activin receptor type 2B binding to receptor type 2B, and the ligand is inhibited from binding to the receptor, inhibit protein signaling associated with the ligand, It may be useful in the prevention or treatment of related diseases.