CCL2 and obesity due to melanocortin 4 receptor deficiency: WAT releases hormones (leptin, adiponectin, etc.)and cytokines (tumor necrosis factor-α (TNF-α), interleukin 6 (Il-6), monocyte chemoattractant protein-1 (Mcp-1), etc.)that modulate whole-body metabolism, insulin resistance, and the systemic low-grade inflammation associated with obesity [9, 10].