BMP-2 (Bone morphogenetic protein 2) is a TGF-beta superfamily cytokine that plays a dominant role in embryonic dorsal-ventral patterning, organogenesis, limb bud formation, and bone formation and regeneration. BMP-2 forms disulfide linked homodimers and heterodimers with BMP-7. BMP-2 signals through heterodimeric complexes of type I receptors (Activin RI, BMPR-IA, or BMPR-IB) and type II receptors (BMP RII or Activin RIIB). It induces chondrocyte proliferation, endochondral bone formation, longitudinal bone growth, and bone and cartilage repair. BMP-2/BMP-7 heterodimers are significantly more potent than BMP-2 homodimers at inducing bone formation in vivo. BMP-2 also promotes the maintenance and repair of colonic epithelium, suppresses neuronal dopamine synthesis and release, induces apoptosis in medulloblastoma cells, and is required for cardiac contractility.