HIF3A and obesity due to melanocortin 4 receptor deficiency: We therefore sought to further elucidate the relationship between HIF3A mRNA expression in visceral and subcutaneous adipose tissue and obesity, but also methylation of CpG-sites in HIF3A. In summary, we show that HIF3A gene expression and methylation in adipose tissue are fat depot specific, and related to obesity and adipose tissue dysfunction.