Considering that activated macrophages have the ability to initially produce proinflammatory cytokines (TNF, IL1β, IL6, and IL12) and, subsequently, induce the production of IL10 in response to LPS, it seems conceivable to suggest that genetic markers within the MAF locus might, at least in part, account for the link between obesity, lipogenesis and inflammation. The gene discussed is IL10; the disease is obesity due to melanocortin 4 receptor deficiency.