TFAP2B and obesity due to melanocortin 4 receptor deficiency: AP-2β can target multiple features of obesity and T2D centrally and peripherally by modulating key-obesity linked genes such as IRS-1, GLUT4, adipocytokines related genes, as well as catecholaminergic and serotonergic genes involved in reward, consummatory behaviour and insulin resistance (Table 3).