Obesity-associated VAT macrophages are largely M1 macrophages, or “classically activated macrophages” that secrete large amounts of inflammatory cytokines including TNF-α, IL-6, IL-12, IL-1β, and monocyte chemotactic protein 1 (MCP-1) (24). The gene discussed is CCL2; the disease is obesity due to melanocortin 4 receptor deficiency.