On the other hand, it must be also pointed out that the increased leptinemia occurring in CR male animals at the age of 5 months compared with controls could also be reflecting the difference in adiposity, but considering that leptin resistance is today recognized as a significant contributor to obesity [21], the excess of fat accumulation would appear to be more a consequence rather a cause of the hyperleptinemia. The gene discussed is LEP; the disease is obesity due to melanocortin 4 receptor deficiency.