TP53 and glioblastoma: While classic glioblastoma commonly exhibits a combination of TERT mutation, EGFR amplification, CDKN2A/B loss, and +7/−10 chromosome copy-number alterations, giant cell glioblastoma often shows TP53 and PTEN mutations, with TP53 mutation being the most frequently observed alteration, present in 90% of cases.