Obesity is often accompanied by low-grade chronic inflammation in adipose tissues, and exhibiting elevated pro-inflammatory cytokines such as tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6) and monocyte chemotactic protein-1 (MCP1). The gene discussed is CCL2; the disease is obesity due to melanocortin 4 receptor deficiency.