EZH2 and cancer: In concordance with the most severe gain of methylation in both cancer types residing over polycomb and bivalent regions, we found that EZH2 binding in normal human astrocytes47 was highly enriched within GBM hyperDMRs, suggesting that these tumors undergo an epigenetic switch involving gain of DNA methylation over regions normally bound by EZH2 in non-malignant astrocytes (Supplementary Table 1).