KRT18 and gastric cancer: We analyzed the expression level of KRT18 in 450 STAD tissue samples from TCGA database and 140 GC samples from GEO database and found a significant overexpression in gastric tumor samples (Figures 1A, 4A), consistent with the biomarker function of KRT18 in GC (Bilici, 2015; Nagel et al., 2018).