Histologically, the IDH wild-type (IDH-wt) and the IDH-mutant, 1p/19q-non-co-deleted diffuse gliomas generally are astrocytoma, while the IDH-mutant, 1p/19q-co-deleted tumors are oligodendroglioma (Wesseling and Capper, 2018). The gene discussed is IDH2; the disease is oligodendroglioma.