The promoter methylation status of O6-methylguanine–DNA methyltransferase (MGMT), DNA-repair gene, remains the strongest predictor of outcome and response to alkylating agents in glioblastoma.85-87  MGMT promoter hypermethylation is associated with better overall survival and better response to temozolomide therapy.42 Conversely, MGMT promoter unmethylated glioblastomas do not benefit from temozolomide and have poorer survival outcomes42,88 (Fig. 4). This evidence concerns the gene MGMT and glioblastoma.