Figure 1

Frequency of hypermethylation (left) and hypomethylation (right) estimated by MS-AFLP arrays. TA, in light blue: tubular adenomas. SSA, in dark blue: sessile serrated adenomas. MSS, in yellow: microsatellite stable carcinomas. MSI, in orange: microsatellite instable carcinomas. Frequencies were calculated as the percentage of probes with log2 ratio value below -1.5 (for hypermethylation) or above 1.5 (for hypomethylation), after filtering the 30% lower-intensity probes from each array. Top graphs, results including all probes after filtering (13,515 probes per array). Bottom graphs, results considering only the probes within ±2.5 Kb of the 5′ end of genes (range: 7,924 to 8,035 probes per array). P-values were calculated by one-way ANOVA followed by Tukey’s HSD multi-hypothesis testing correction. Only p-values below 0.05 are shown.