RPGRIP1L and obesity due to melanocortin 4 receptor deficiency: Considering the important role of RPGRIP1L in cilium function26,31, and the critical link between cilium function, hyperphagic obesity and cognition (e.g. Bardet-Biedl syndrome)34, it is tempting to speculate that changes in brain expression of RPGRIP1L induced by FTO SNPs may also have an impact on impulsive behaviors.