It plays an essential role in many physiological and pathological processes by binding specific sequence sites ACANNTGT. A causal cis-regulatory variant in the first intron of the FTO gene, which has been reported to be most associated with obesity, leads to activation of downstream targets IRX5 and IRX3 through long range enhancer promoter interactions. Here, IRX5 is linked to obesity due to melanocortin 4 receptor deficiency.