BMP (Bone Morphogenetic Protein) is a secreted signaling molecule and a subfamily of the TGF-β (Transforming Growth Factor-beta) superfamily. Initially identified as regulators of cartilage and bone formation, BMPs are typically involved in embryonic development and morphogenesis of various tissues and organs. BMP-2, BMP-4, and BMP-7 function in the regulation of hematopoietic tissue specification in the mesoderm. They regulate the proliferation and differentiation of highly purified primitive human hematopoietic cells derived from both adults and neonates. BMP-4, also known as Bone Morphogenetic Protein 4, forms a homodimer linked by disulfide bonds. It has been shown that BMP-4 is also involved in the differentiation of sympathetic neurons, enhancing the formation of adrenergic sympathetic neurons in neural cell cultures.