EGFR and astrocytoma (excluding glioblastoma): Those are conventional glioblastoma (IDH wild type) presenting with the classical histological hallmarks of a grade 4 glioma; molecular glioblastoma (IDH wild type), harboring any of the glioblastoma-defining genetic alterations, namely TERT promotor mutation, EGFR amplification, or +7/−10 chromosomal copy number changes, without exhibiting the typical histological appearance; and grade 4 astrocytoma (IDH mutant, 1p/19q non-codeleted).