Since tissue resident macrophages release pro-inflammatory cytokines like tumor necrosis factor alpha (TNF-α), Interleukin 6 (IL-6), Interleukin 1β (IL-1β), or monocyte chemoattractant protein-1 (MCP-1) (Kershaw and Flier, 2004), obesity is seen as a state of chronic inflammation thereby not only influencing the immune response but also several metabolic processes like energy homeostasis, glucose and lipid metabolism (Coelho et al., 2013). The gene discussed is CCL2; the disease is obesity due to melanocortin 4 receptor deficiency.