BMPs (bone morphogenetic proteins) belong to the TGF-beta superfamily of structurally related signaling proteins. Members of this superfamily are widely represented throughout the animal kingdom and have been implicated in a variety of developmental processes. Proteins of the TGF-beta superfamily are disulfide-linked dimmers composed of two 12-15 kDa polypeptide chains. As implied by their name，BMPs initiate，promote and regulate bone development，growth，remodeling and repair. BMP-8 (also designated OP-2) is thought to be involved in early development，as detectable expression has not been found in adult organs.
