The media layer of the abnormally remodeled vessels from eNOS knockout mice shows hyperplasia, as evidenced by the significant increase in wall thickness, number of medial nuclei, and the incorporation of bromodeoxyuridine, which reminisce the arterial thickening in hypertension and atherosclerosis of human patients (Moroi et al., 1998). This evidence concerns the gene NOS3 and atherosclerosis.