In Figure 1, obesity and the typical accumulation of fat in adipose tissue, secretion of pro-inflammatory cytokines such as interleukins 1 and 6 (IL-1 and IL-6), as well as tumor necrosis factor-alpha (TNFa) and free fatty acids (FFAs), are shown by the orange arrows. The gene discussed is TNF; the disease is obesity due to melanocortin 4 receptor deficiency.