CCL2 and obesity due to melanocortin 4 receptor deficiency: Signatures of the insulin-resistant state, including obesity-related chronic low-grade inflammation and aberrant production of adipokines (leptin, adiponectin, visfatin, and plasminogen activator inhibitor-1) and proinflammatory cytokines (interleukin [IL]-6, IL-8, monocyte chemoattractant protein-1 [MCP-1] and tumor necrosis factor-α (TNF-α), are established drivers of cancer development [2–4].