In the context of obesity, they showed that most of the identified loci harbour genes involved in pathways affecting neuro-circuits of appetite and satiety regulation (BDNF, MC4R and NEGR) [35–37], energy and lipid metabolism (FTO, RPTOR and MAP2K5 [13, 27, 38], insulin secretion and action (TCF7L2, IRS1) [13, 38] as well as adipogenesis [14]. This evidence concerns the gene FTO and obesity due to melanocortin 4 receptor deficiency.