Bone morphogenetic protein receptor type II or BMPR2 is a serine/threonine receptor kinase. It binds Bone morphogenetic proteins, members of the TGF beta superfamily of ligands, which are involved in paracrine signalling. BMPs are involved in a host of cellular functions including osteogenesis, cell growth and cell differentiation. Signaling in the BMP pathway begins with the binding of a BMP to the type II receptor. This causes the recruitment of a BMP type I receptor, which it phosphorylates. The Type I receptor phosphorylates an R-SMAD a transcriptional regulator.