The 2016 World Health Organization (WHO) classification of gliomas identified three subtypes based on molecular and histological features: (1) diffuse isocitrate dehydrogenase (IDH) wild-type astrocytoma (IDH wild-type without 1p/19q-codeleted), (2) diffuse IDH mutant astrocytoma (IDH mutant without 1p/19q-codeleted), and (3) oligodendroglioma (IDH mutant with 1p/19q-codeleted) [2]. The gene discussed is IDH3A; the disease is astrocytoma (excluding glioblastoma).