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 subunits of a disulfide-linked homodimer, or alternatively, a heterodimer, with the related protein, growth differentiation factor 9 (GDF9). This protein plays a role in oocyte maturation and follicular development, through activation of granulosa cells. Defects in this gene are the cause of ovarian dysgenesis and are associated with premature ovarian failure. [provided by RefSeq, Aug 2016]