The presence and role of hypoxia in human obesity is not well described as reviewed by Ruiz-Odeja (20) but stabilisation of hypoxia inducible factor-1α (HIF-1α) in hypoxia stimulates the expression of a range of genes involved in angiogenesis, glycolysis, and erythropoiesis (7, 11, 20–23). The gene discussed is HIF1A; the disease is obesity due to melanocortin 4 receptor deficiency.