NOS3 and endothelial dysfunction: Chin et al., in in vivo murine models, showed that the inhibition of endothelial nitric oxide synthase (eNOS) was associated with the impairment of angiogenesis not because of aging per se but because of all the mechanisms (including endothelial dysfunction, smooth muscle cell disruption, increased oxidative stress, and DNA damage) that mark it [60,61].