RETSAT and obesity due to melanocortin 4 receptor deficiency: However, obesity in humans and mice, irrespective of diet-induced or genetic, associates with reduced RetSat expression in white adipose tissue (WAT), implying additional functions in adipose tissue [2] and underlining the earlier reported highly dynamic expression of RetSat in conditions related to type 2 diabetes and insulin resistance as the top differentially-regulated gene [16].