CCL18 and cancer: In one respect, CCL18 in TME binds to its receptors (PITPNM3 12, CCR6 28 and CCR8 29-31) on the membrane of tumor cells, activates multiple carcinogenesis associated signaling pathways including NF-κB, PI3K/Akt, Wnt/β-catenin and mTOR etc, which in turn accelerates the progression of diverse human cancers including head and neck cancer 13, 14.