Genetic deficiency of either PrRP or GPR10 results in late-onset obesity and the loss of anorectic responses to CCK (Bechtold and Luckman, 2006, Gu et al., 2004, Takayanagi et al., 2008, Watanabe et al., 2005). This evidence concerns the gene PRLHR and obesity due to melanocortin 4 receptor deficiency.