Some examples of models used in the study of GBM involve deletion of the tumor suppressor gene p53, which harbors a conditional allele of the tumor suppressor Nf [68]; the combined Cdkn2a knockout mouse models, with upregulation of Kras and Akt by viral induction [69]; the combined conditional knockout of the tumor suppressor genes p53, Nf1, and Pten [70]; and others. This evidence concerns the gene TP53 and glioblastoma.