Bone morphogenetic protein-2 (BMP-2) is a kind of bone growth regulator, belonging to protein transforming growth factor-β(TGF-β) superfamily. BMP-2 protein is involved in hedgehog pathway, TGF-β signaling pathway and cytokine-cytokine receptor interaction. BMP-2 and BMP-7 are osteogenic BMP, which have been proved to be effective in inducing osteoblast differentiation in many cell types. The active form of BMP-2 can be composed of dimers of two identical proteins or heterodimers of two related bone morphogenetic proteins.