Mice lacking the CCR2 receptor for the chemokine MCP-1/CCL-2 fail to develop signs of neuropathic pain following nerve injury (118, 321), a MCP-1/CCL2 antagonist blocks paclitaxel-induced neuropathic pain (52) and over expression of CCR2 enhances nociceptive responses (322). The gene discussed is CCL2; the disease is injury.