IDH3A and glioblastoma: According to the latest 2021 World Health Organization (WHO) Central Nervous System (CNS) 5 classification [4, 5], adult-type diffuse gliomas are classified into 3 types: (1) astrocytoma, isocitrate dehydrogenase (IDH) mutant (WHO grades 2–4); (2) oligodendroglioma, IDH mutant and 1p/19q codeleted (WHO grades 2 and 3); and (3) glioblastoma (GBM), IDH wild type (WHO grade 4) [5].