GDF3 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. The function of this protein is unknown, but expression studies suggest it may be involved in regulation of the adult lymphatic and erythroid systems and embryonic development.