IDH3A and glioblastoma: According to the 2021 World Health Organization (WHO) Classification of Tumors of the Central Nervous System, diffuse gliomas are classified into isocitrate dehydrogenase (IDH)-mutant astrocytomas (WHO Grades 2–4), IDH-mutant and 1p/19q codeleted oligodendrogliomas (WHO Grades 2 and 3), and IDH-wildtype glioblastomas (GBM, WHO Grade 4) (Louis et al., 2021).