Density and distribution of methylated CpG within the 5′ CpG island of p14ARFflanking exon 1β. Depicted is the distribution of methylated CpG in tumors (up) and corresponding adjacent colon mucosa (down) from 10 patients. For each case, 10 independent clones (represented on horizontal line (a) to (j) were examined. The circles on the vertical line represent the 27 CpG (CpG 1 to 27) sites analyzed for each individual clone. Note that the translation start site is located between CpG sites 8 and 9. An empty circle indicates that the concerned CpG site is unmethylated, a black circle indicates that the concerned CpG site is methylated. For each tumor, the microsatellite instability (MSI) status and p53 immunohistochemistry are indicated. MSI-H, microsatellite instability-high; MSS, microsatellite-stable; p53 D, diffuse pattern of p53 expression, p53 R, restricted pattern of p53 overexpression.