IDH1 and glioblastoma: Many previous studies have suggested that the prevalence of IDH1 mutations is particularly high in LGGs with 1p/19q deletion [10], TP53 mutation [5], and O 6-methylguanine-DNA methyltransferase (MGMT) gene promoter methylation [11], which has been shown to play a role in predicting survival in patients with newly diagnosed GBM [11].