There are several factors which may enhance the EVA process such as atherosclerosis via intima–media thickening, smoking through increased production of the reactive oxidative species (ROS), hypertension via activation of the renin–angiotensin system and decreased cell proliferation (Bots and Grobbee, 2002; Hansson, 2005; Nilsson, 2008b). This evidence concerns the gene REN and atherosclerosis.