IDH1 and oligodendroglioma: Further important molecular features implemented in the WHO CNS5 classification of gliomas include co-deletion of 1p/19q (oligodendroglioma, WHO grade 2-3), homozygous CDKN2A/B deletion (astrocytoma, IDH-mutant, WHO grade 4), as well as the presence of alterations in MYB, MYBL1, MN1, YAP1, MYCN, FOXR2, BCOR, SMARCB1, FET-CREB, and DICER1 (39).