Irisin expression is regulatedby peroxisome proliferator-activated receptor gamma coactivator (PGC)-1α.PGC-1α regulates uncoupling protein (UCP)-1 expression to promotethermogenesis in brown adipose tissue.13−15 UCP-1 expression islower in white adipose tissue, which possess the ability to serveas a possible target for obesity treatment.16 Previous studies have shown that brown adipose tissue positivelyaffects metabolism and energy balance in mice. This evidence concerns the gene PPARGC1A and obesity due to melanocortin 4 receptor deficiency.