Obesity is often characterized by a state of chronic low-grade inflammation, with the increased production of pro-inflammatory cytokines such as tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and monocyte chemoattractant protein-1 (MCP-1) [117,118]. The gene discussed is IL6; the disease is obesity due to melanocortin 4 receptor deficiency.