According to the fifth edition of the WHO Classification of Tumors of the Central Nervous System (WHO CNS5), adult-type diffuse gliomas can be divided into isocitrate dehydrogenase-wildtype glioblastoma (IDH-wildtype GBM), IDH-mutant astrocytoma, and IDH-mutant and 1p/19q-codeleted oligodendroglioma (2). The gene discussed is IDH3A; the disease is astrocytoma (excluding glioblastoma).