It is well known that estrogenic signaling prevents accumulation of visceral fat, increases central sensitivity to leptin, increases the expression of insulin receptors in adipocytes, and decreases the lipogenic activity of lipoprotein lipase in adipose tissue, thus preventing the development of obesity and insulin resistance (Clegg et al., 2006). The gene discussed is INSR; the disease is obesity due to melanocortin 4 receptor deficiency.