Growth differentiation factor 1 (GDF1) is a protein that in humans is encoded by the GDF1 gene. This gene encodes 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 that 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. Studies in rodents suggest that this protein is involved in the establishment of left-right asymmetry in early embryogenesis and in neural development in later embryogenesis. This protein is transcribed from a bicistronic mRNA that also encodes the longevity assurance gene.