Tumor and non-tumor samples differed significantly in the expression of 10/22 genes (Fig. 1a): CCNB1, CLDN4, CLDN6, MMP2, MUC1 (all: p < 0.05), BAG1, SERPINB3 (all: p < 0.01), CD44 (standard variant), MKI67, and MYBL2 (all: p < 0.001). This evidence concerns the gene CLDN4 and neoplasm.