Fig. 1
CpG islands and heterogeneity of methylation statuses for each individual CpG site in the MGMT promoter region. a Map of the distribution of CpGs in the MGMT 5′ CpG island. CpGs 72–82, which are most commonly used in pyrosequencing, are shown in the lower panel. The eight and seven CpGs used in this study are indicated by gray and light blue lines, respectively. CpGs 74–78 and 76–79 are indicated by black and dark blue lines, respectively. b Methylation levels of each CpG were depicted in a heatmap for cohort A. Average refers to the average methylation level of CpGs 75–82. A part of the heatmap (with average methylation level < 4%) was displayed again in another heatmap (in the lower left corner) with a more discriminative color bar. c Methylation levels in patients with average methylation levels of 4–16% were compared. The mean and range were indicated by the black point and red line, respectively
