MGMT and glioblastoma: Despite these well-known relationships, the prognosis of glioblastoma, which account for up to 70% of high-grade malignant glioma, is bleak as the median length of survival is only 14.6 months (12.6 and 23.4 months in the MGMT-unmethylated and MGMT-methylated subgroups, respectively) [27].