Isocitrate dehydrogenase (IDH)-wildtype gliomas (gliomas that do not have mutations in the IDH genes), resembling glioblastomas, exhibit worse prognoses compared to diffuse IDH-mutated gliomas (IDH mutation confirmed on IHC), characteristic of lower-grade astrocytomas and oligodendrogliomas. Here, IDH1 is linked to oligodendroglioma.