Thus, mice lacking Gq/11 at the paraventricular nucleus of the hypothalamus develop severe hyperphagic obesity and are unable to respond to MC4R agonists [37], while obese mice with a MC4R-F51L mutation associated with human obesity, have a specific defect in Gq/11 signaling [38]. Here, MC4R is linked to obesity due to melanocortin 4 receptor deficiency.