Bone Morphogenetic Protein-2 (BMP-2) is an extracellular multifunctional signaling cytokine that is also a member of the TGF-β family. BMP-2 can bind with the TGF-β receptor to active SMAD protein signal transduction. Moreover, it engages in the path of signals such as Wnt and Notch. BMP-2 plays an essential role in the growth of hard bones and cartilage and involved in the differentiation of osteoblasts.