GBM tumors with wild-type isocitrate dehydrogenase 1 and 2 (IDHwt) carries a worse prognosis than those harboring IDH1/2 mutations (IDHmut) [156], while the presence of O6-methylguanine-DNA methyltransferase (MGMT) methylation is associated with a better response to temozolomide (TMZ) chemotherapy [157]. This evidence concerns the gene MGMT and glioblastoma.