GPX7 and colon carcinoma: In the small number of MSI (N = 20) and MSS (N = 40) colon carcinomas in our study, we found statistically significant differential hypermethylation in MSI compared to MSS tumors for 4 of 13 individual markers [HIN1, ARHGEF7, GPX7, and COL6A2 (P < 0.0001, P < 0.0001, P = 0.0003, P = 0.0010, respectively; Additional file 1: Fig. S6)].