Experimental studies found that ECP reduces endothelial damage, arrests vascular smooth muscle cell proliferation and migration, decreases the proliferating cell nuclear antigen proliferative index, suppresses extracellular matrix formation, and eventually inhibits intimal hyperplasia and the development of atherosclerosis by increasing the arterial wall shear stress, which in turn activates the endothelial-derived nitric oxide (NO) synthase/NO pathway and probably suppresses extracellular signal-regulated kinase 1/2 overactivation (31). This evidence concerns the gene MAPK3 and atherosclerosis.