HDAC9 and calcification: An in vivo study recapitulated vSMC differentiation into an osteogenic-like phenotype, by demonstrating that MGP (matrix gla protein)-deficient mice develop severe calcification of vSMCs in arterial blood vessels.105 Interestingly, MGP-deficient mice also lacking HDAC9 (histone deacetylase 9) had a 40% reduction in aortic calcification with improved survival.120 Thus the presence of HDAC9 causes progression toward the osteogenic-like vSMC phenotype induced by the absence of MGP.