Bone Morphogenetic Protein-8 （BMP-8） is an extracellular multifunctional cytokine that is also a member of the TGF-β family. BMP-8 can bind with TGF-β receptor and is involved in SMAD protein signal transduction. In addition, BMP-8 participates in the downregulation of insulin secretion that lets the heat stabilize. Moreover, it participates in ossification and is essential to cartilage and hard bone development.