NOS3 and Hypercholesterolemia: During hypercholesterolemia, oxidized low-density lipoproteins (Ox-LDL) may trigger the expression of pro-oxidative enzymes in the vascular wall that contribute to the generation of ROS, which at high concentrations, elicit endothelial dysfunction in part by affecting eNOS function and by inactivation of nitric oxide [28,29,30,31].