In addition, TCF21 is activated early on in coronary artery disease and directly inhibits SMAD3-mediated gene expression, thereby reducing expression of the contractile markers.86 Together, these studies point to TCF21 as a regulator of vSMC phenotype switching toward a protective fibroblast-like vSMC population in atherosclerosis. The gene discussed is TCF21; the disease is coronary artery disorder.