Promoter methylation status in normal colon mucosa and different lesion types. Scatter plots of the levels of SFRP2, WIF-1, DKK3, SOX17 methylation. On the y-axis levels of DNA methylation are shown; On the x-axis normal colon mucosa (NC-M), nonpolypoid adenomas (NP-A), polypoid adenomas (P-A) and carcinomas (C) are indicated. The dotted line indicates the methylation cut off value based on the 99% CI of normal colorectal mucosa. Asterisks indicate a statistical significant difference.