BMP Family Bone morphogenetic proteins ( BMPs ) are a group of growth factors also known as cytokines and as metabologens. BMPs are secreted signaling molecules that belong to the transforming growth factor β family of growth and differentiation factors. Bone morphogenetic proteins are synthesized as large precursors consisting of a signal peptide, a prodomain and a carboxy terminal region of 100 to 125 amino acids. Within the carboxy terminal region of most bone morphogenetic ptoteins are seven highly conserved cysteine residues important for correct folding of these dimeric molecules. Bone morphogenetic protein receptors are members of a larger family of serine threonine kinases that include the receptors for transforming growth factor vetas, activins and inhibins.