IDH1 and astrocytoma (excluding glioblastoma): In adults, gliomas are classified based on molecular markers that influence patient prognosis: IDH-mutant/1p19q-codeleted oligodendrogliomas, with the best prognosis; IDH-mutant/1p/19q-non-codeleted astrocytomas, with an intermediate prognosis; and IDH-wildtype astrocytomas (glioblastoma), with the poorest prognosis [64].