NOS3 and atherosclerosis: Therefore, the endothelium-derived cNOS expression or activity as well as the production of endothelial NO is decreased, whereas the activity of vascular smooth muscle cell (VSMC)-expressed iNOS is increased,11,12 resulting in increased NO free-radical production, which stimulates cell apoptosis and collagen degradation and promotes the development of atherosclerosis.11,13 NO free radicals could also synthesise peroxynitrite through a reaction with superoxide anion, thus causing further tissue damage.12