In obesity, the adipose tissue secretes cytokines and chemokines such as TNF-α and monocyte chemoattractant protein 1 (MCP-1),39,40,41,42,43 resulting in infiltration of neutrophils,44 monocytes, and differentiation to predominantly M1 macrophages.40 The gene discussed is CCL2; the disease is obesity due to melanocortin 4 receptor deficiency.