CXCL9 and mucositis: Previous studies have reported that several inflammatory mediators are involved in 5-FU-related mucositis pathogenesis, including chemokine (C-X-C motif) ligand 4 (CXCL4)3, interleukin-4 (IL-4)4, interleukin-1β (IL-1β)5, chemokine (C-X-C motif) ligand 9 (CXCL9)6, TGF-β6, platelet activating factor (PAF)7, substance P and serotonin8.