This gene encodes a secreted ligand of the TGF-beta (transforming growth factor-beta) superfamily of proteins. Ligands of this family bind various TGF-beta receptors leading to recruitment and activation of SMAD family transcription factors that regulate gene expression. The encoded preproprotein is proteolytically processed to generate each subunit of the disulfide-linked homodimer. This protein is important in embryogenesis and likely plays a role ocular and skeletal development. Mice lacking a functional copy of this gene exhibit defects in early embryonic development resulting in embryonic lethality. [provided by RefSeq, Aug 2016]