INS and obesity due to melanocortin 4 receptor deficiency: Early and acute adipocyte ablation of Fam20c in the course of obesity resulted in substantial improvements in insulin signaling with elevations in insulin-stimulated p-AKT by 1.6-fold in SC WAT, 1.5-fold in VIS WAT, 1.9-fold in liver, and 2.9-fold in skeletal muscle compared with controls, indicating enhanced insulin responsiveness in multiple metabolic tissues (Figure 4, H–M).