PRKAA2 and obesity due to melanocortin 4 receptor deficiency: Several recent reports have confirmed the remarkable role, previously described by Enkhjargal and colleagues, associated with AMP-activated protein kinase (AMPK) production in the treatment of metabolic disorders, including diabetes mellitus and obesity, in which vascular endothelial dysfunction is the main pathophysiological mechanism [66,67,68,69,70,71,72].