Interestingly, when expression levels of only tumor tissues with different localization were compared, tumor localized in colon showed significantly increased levels of almost all analyzed MMR genes, namely MSH2 (1.68, P < 0.0001), MSH3 (1.27, P = 0.001), MSH6 (1.43, P = 0.004), PMS2 (1.16, P = 0.005) and EXO1 (1.30 fold change, P = 0.02) (Figure 2; Additional file 1: Table S3a). The gene discussed is EXO1; the disease is neoplasm.