MGMT and glioblastoma: Among others, Bady et al. [1], who investigated the methylation pattern of glioblastomas based on 450 K analyses, found that CpGs 33 and 87 were the sites of most prognostic relevance, out of the 18 CpG sites that cover the CpG-island of MGMT. Notably, CpG 87 is also within the enhancer region and in proximity to the CpGs highlighted in the Random Forest analysis as being strongly correlated with overall survival (CpGs 86 and 88) (Fig. 3).