IDH1 and astrocytoma (excluding glioblastoma): The overall epigenetic silencing of the glycolytic pathway might explain the slow-growing nature of IDH-mutated glioma as compared with their IDH wild-type counterparts.30,31 In support of this hypothesis, in a recent study, the acquisition of the Warburg phenotype was associated with more aggressive gliomas and was found to occur at the CpG island methylator phenotype (G-CIMP) in gliomas described below, which is specific for astrocytoma.32