IDH1 and glioblastoma: Specifically, these include: Pilocytic astrocytoma (CNS WHO grade 1); Oligodendroglioma, IDH‐mutant and 1p/19q‐codeleted (CNS WHO grades 2 and 3); Astrocytoma, IDH‐mutant (CNS WHO grade 3); Astrocytoma, IDH‐mutant with CDKN2A/B homozygous deletion (CNS WHO grade 4); Glioblastoma, IDH‐wildtype (CNS WHO grade 4); and Glioblastoma, IDH‐wildtype with TERT promoter mutation, EGFR amplification, or chromosome 7 gain/chromosome 10 loss (CNS WHO grade 4) [22, 23].