Nitric oxide (NO) synthesized in endothelial cells from L-arginine by endothelial nitric oxide synthase (eNOS) is the major source of NO in brain vessels and an important signaling molecule in vasculogenesis [1–3], cerebral blood flow regulation [3, 4], atherosclerosis and thrombosis [5–8], and amyloid-beta (Aβ) production [9–12]. Here, NOS3 is linked to atherosclerosis.