IDH1 and glioblastoma: However, in the most recent WHO CNS 2021 classification, the presence of epidermal growth factor receptor (EGFR) amplification and/or whole chromosome 7 gain and whole chromosome 10 loss (+7/−10) and/or telomerase reverse transcriptase (TERT) promoter mutations indicates a molecular diagnosis of glioblastoma, WHO CNS grade 4, in isocitrate dehydrogenase (IDH)-wt astrocytic gliomas [2,3].