It is now recognized that the chronic inflammation associated with obesity is mediated in part by various chemokines, hormones and cytokines (such as TNF-α and IL1-β), and that it plays a key role in a constellation of diseases that includes hypertension, type 2 diabetes and cardiovascular disease, and is often referred to as metabolic syndrome38, 39, 40, 41, 42, 43. The gene discussed is TNF; the disease is obesity due to melanocortin 4 receptor deficiency.