FGF21 and obesity due to melanocortin 4 receptor deficiency: The counteraction of obesity by AAV8‐hAAT‐FGF21 treatment was parallel to a dose‐dependent decrease in the weight of the main white adipose tissue (WAT) depots, such as the epididymal (eWAT), inguinal (iWAT), and retroperitoneal (rWAT) fat pads, both in animals treated as young adults and in those treated as adults (Fig 1C and Appendix Fig S1C).