GDF-3 is a member of the TGF-beta superfamily of growth and differentiation factors, and is highly homologous to GDF-9. Unlike most TGF-beta family members, GDF-3 and GDF-9 are not disulfide-linked dimers. GDF-3 is expressed in adult bone marrow, spleen, thymus, and adipose tissue. The expression of GDF-3 is upregulated in high-fat-fed wild-type FABP4/aP2 null mice and was associated with obesity, but not with the related hyperglycemia/hyperinsulinemia that characterizes Type 2 diabetes. Recombinant Human GDF-3 is a 26.0 kDa non-disulfide-linked homodimer containing two 114 amino acid polypeptide chains.