INS and obesity due to melanocortin 4 receptor deficiency: Indeed, a sexual dimorphism has been described in mice that affected adipose tissue accumulation and gene expression as well as insulin sensitivity [37], [38], [39] and sex hormones such as estrogens have been convincingly reported to alter adipocyte biology and to impact on obesity-related co-morbidities, such as insulin resistance [40], [41], [42].