MGMT and glioblastoma: It has potential to be an additional tool for stratification of patients as DNA methylation has been used for tumor classification and subtyping (e.g. the brain tumor medulloblastoma) [31, 32, 39] and is now entering clinical diagnostic use [47, 48], and also as a biomarker for predicting treatment response (e.g. MGMT methylation in the high-grade tumor GBM) [49].