Hence, the observed results might be primarily because of neuron specific activity of Wdr13. However, since brain metabolism is altered by changes in levels of circulating insulin (Bingham et al., 2002) and in obesity (Yau et al., 2012), studying Wdr13−/0 mice at 10 months might not distinguish properly between the brain-specific function of Wdr13 and changes in systemic metabolism. This evidence concerns the gene WDR13 and obesity due to melanocortin 4 receptor deficiency.