REN and obesity due to melanocortin 4 receptor deficiency: The mechanisms by which obesity causes RAAS activation are complex and include dysregulated adipose tissue secreting angiotensinogen, aldosterone, and mineralocorticoid-releasing factors (13, 14, 16); endothelial dysfunction causing disturbed renal blood flow (14, 16, 17); sympathetic nervous system activation inducing renin secretion (16, 18, 19); and reduced expression of angiotensin-converting enzyme 2 (20-22).