Bone morphogenetic protein 4 （BMP4） is a multifunctional ligand protein belonging to TGF β Family. BMP4 is expressed by endothelial cells （EC） in response to hypoxia and promotes proliferation of vascular smooth muscle cells （SMC）. For example, it inhibits the proliferation of SMCs isolated from the proximal pulmonary artery while inducing the proliferation of SMCs isolated from the distal pulmonary artery. BMP4 seems to be a marker and driver of vascular calcification, especially in atherosclerosis. BMP4 induces angiogenesis, endothelial cell （EC） proliferation, and migration. BMP4 is differentially expressed in calcified atherosclerotic plaque, which is the junction between atherosclerotic vascular calcification and normal bone formation mechanism. BMP4 increases plaque formation, promotes oxidative stress, endothelial dysfunction and osteogenic differentiation through its proinflammatory and atherogenic effects.