IRX3 and obesity due to melanocortin 4 receptor deficiency: For example, SNPs associated with obesity and type-2 diabetes that are located in noncoding regions of the FTO gene locus interact with the promoter of the IRX3 gene at megabase distances, thus affecting the expression of IRX3, which regulates body weight in mice (Smemo et al., 2014; Claussnitzer et al., 2015).