The protein encoded by this gene is a member of the bone morphogenetic protein (BMP) family and the TGF-beta superfamily. This group of proteins is characterized by a polybasic proteolytic processing site which is cleaved to produce a mature protein containing seven conserved cysteine residues. The members of this family are regulators of cell growth and differentiation in both embryonic and adult tissues. This gene is thought to encode a secreted protein which negatively regulates skeletal muscle growth. Acts specifically as a negative regulator of skeletal muscle growth. [SUBUNIT] Homodimer; [TISSUE SPECIFICITY] Expressed specifically in developing and adult skeletal muscle. Weak expression in adipose tissue. Belongs to the TGF-beta family.