Bone morphogenetic protein 4 (BMP-4) is a member of the bone morphogenetic protein family which belongs to the TGF-β superfamily. This protein is a vital regulatory molecule that functions throughout bone and cartilage development, specifically tooth development, limb formation, bone induction, and fracture repair. In human embryonic development, BMP- 4 is required for the early differentiation of the embryo and establishing of a dorsalventral axis.