Previous studies showed that upregulation of endothelial nitric oxide synthase (e-NOS) expression and activity has its important role in the protection of endothelium.14–16 e-NOS could stimulate endothelium-dependent relaxation and protect against the development of VCAM-1-induced endothelial dysfunction.17 However, to our knowledge, little is known about the role of cigarette smoke in this atherosclerotic inflammatory process. This evidence concerns the gene NOS3 and endothelial dysfunction.