Non-coding variations represented by SNPs in the first intron of FTO are the strongest genetic risk factors of polygenic obesity in humans (Dina et al., 2007; Frayling et al., 2007; Cecil et al., 2008; Speakman et al., 2008; Tanofsky-Kraff et al., 2009). Here, FTO is linked to obesity due to melanocortin 4 receptor deficiency.