The monocyte chemotactic proteins 1 and 3 (MCP-1, MCP-3; synonym CCL2 and CCL7) and the macrophage inflammatory proteins 1α and 1β (MIP-1α, MIP-1β; synonym CCL3 and CCL4) recruit effector cells to the site of infection and activate immune cells by stimulating further release of inflammatory mediators [35,36]. The gene discussed is CCL2; the disease is infection.