NOS3 and obesity due to melanocortin 4 receptor deficiency: Although the available evidence convincingly suggests that potential benefits of UnGhr on high-fat diet (HFD)-induced endothelial dysfunction and early vascular disease exist, no information is available on the impact of UnGhr on endothelial vasorelaxation, eNOS function, vascular oxidative stress and atherosclerosis burden in the setting of obesity and insulin resistance.