GDF-11 is a myostatin-homologous protein that acts as an inhibitor of nerve tissue growth. GDF-11 has been shown to suppress neurogenesis through a myostatin-like pathway, which involves arrest of progenitor cell-cycle in the G1 phase. Similarities between myostatin and GDF-11, which are 90% identical in their amino acid sequence, suggests that the regulatory mechanisms responsible for maintaining proper tissue size during neural and muscular development might be the same. Recombinant human GDF-11 is a 25.0 kDa disulfide-linked homodimer containing two 109 amino acid polypeptide chains. It is highly homologous to myostatin/GDF-8 sharing 90% amino-acid sequence identity.