CLDN6 and neoplasm: The RT-PCR results showed that the CTLA4 and ENTPD2 were highly expressed in normal gastric mucosal epithelial cell lines (GES-1), while the EMB, CLDN6, VWF and AKR1B1 were highly expressed in human GC cell lines (MKN45 and AGS), and the expression of GPR15 had no significant difference between normal and tumor cell lines (Supplementary Figure S4A).