CXCL16 and irritable bowel syndrome: Elevated levels of “C chemokines” (CXCL16) and “CC chemokines” (MCP-1 and MIP-1β) in IBS patients suggest that these small signaling proteins, which induce the chemotaxis of monocytes, macrophages, mast cells, T lymphocytes, eosinophils, and neutrophils to sites of inflammation may play a role in the pathophysiology of IBS.