Figure 1

Image plot showing CpG methylation data from 264 DNA samples as assessed by pyrosequencing. Samples are grouped by pathological category from normal (bottom) to carcinoma (top). Rows represent individual samples. LRN: low-risk normal mucosa from patients with no history of CRC; HRN: high-risk normal mucosa from patients with CRC; HP: hyperplastic polyps; Ad: adenomas; pT: primary colorectal adenocarcinomas and M: metastatic adenocarcinomas to the liver. Columns show the methylation data for each of the CpG dinucleotides analyzed grouped by gene. A scale shown on the right side of the figure represents the colour spectrum reflecting the percentage of CpG methylation as detected by pyrosequencing. White spaces within the plot indicate missing values due to failure of samples to meet bisulfite conversion or pyrosequencing controls or due to lack of DNA. The subset of CIMP and MSI positive primary colorectal carcinomas is highlighted on the plot.