It has been reported that overexpression of SLC22A17 associated with poor prognosis of cancer, such as endometrial carcinoma, gliomas and hepatocellular [28–30], and Lipocalin-2 (LCN2) has the potential to alter immune cell infiltration and the tumor microenvironment in pancreatic ductal adenocarcinoma by downregulation of LCN2-specific receptor SLC22A17 [31]. Here, LCN2 is linked to pancreatic ductal adenocarcinoma.