Background: The BMPs belong to the TGF-Beta superfamilyBMPs stimulate the production of bone matrix proteins and thereby alter stromal cell and osteoclast proliferation, a key step in bone marrow development. In addition to promoting ectopic bone and cartilage development, BMPs regulate the growth, differentiation, chemotaxis, proliferation, and apoptosis of various cell types, including mesenchymal cells, epithelial cells, hematopoietic cells, and neuronal cells. BMPs also play a role in dorsal/ventral patterning. BMP3, highly expressed in lung, ovary and small intestine, participates in cartilage and bone formation. BMP3 and BMP2 genes map to conserved regions between human and mouse.