CCL18 and pancreatic ductal adenocarcinoma: High enriched CCL18 was tightly related to poor prognosis in multiple solid cancers, such as pancreatic ductal adenocarcinoma 17, 18, ovarian cancer 19, gallbladder carcinoma 20 and gastric cancer 21 etc. However, the clinical significance and especially prognostic value of serum CCL18 in patients with LSCC remains unclear.