Additionally, in some studies, cytokines such as chemokine (C-C motif) ligand-16 (CCL-16) [72], macrophage migration inhibitory factor (MIF), and monocyte chemotactic protein-1 (MCP1 or CCL2) [73] were found to be elevated in the serum of IBS patients compared with controls. This evidence concerns the gene CCL2 and irritable bowel syndrome.