Figure 2

Clustering of the samples according to their methylation profile. Hypermethylation is indicated in red. Hypomethylation is indicated in blue. Samples are shown on top of the heatmap. In white, the normal tissue DNA mix used as reference. Colors for the four tumor groups are as in Figure 1. On the right side of the heatmap, the genes associated to MS-AFLP probes. AXIN2 probes are indicated in black. Clustering was performed by complete linkage using Pearson’s correlation on a subset of MS-AFLP probes previously selected by ANOVA. Group 1 contains mostly tubular adenomas and MSS carcinomas. Group 2A contains the majority of MSI carcinomas, and 5 MSS carcinomas. All the sessile serrated adenomas are grouped in 2B1 and 2B2. Below the heatmap, in black, cases positive for mutation in BRAF or KRAS, or hypermethylation of hMLH1.