HIF3A and obesity due to melanocortin 4 receptor deficiency: Genome-wide association studies of human fat lypolysis identify HIF3A expression in mature and precursor adipocytes and knock-down of HIF3A in human MSCs increased fatty acid oxidation, suggesting that reported studies and our results support the hypothesis that HIF3A is relevant in adipogenesis and methylation is secondary to disrupt the metabolism leading to obesity.