Among these 75 IDH-mutant cases, a group of cases (n = 50) receiving at least 3 cycles of TMZ treatment was used as cohort A to study the predictive value of MGMT promoter methylation levels in IDH-mutant GBM, and a group of IDH-wildtype cases (n = 99) was used as a comparison reference. This evidence concerns the gene IDH2 and glioblastoma.