TP53 and glioblastoma: There is also often loss of phosphatase andtensin homologue (PTEN), known as the tumor suppressor gene negativelycontrolling the PI3K signaling pathway.7 Specific molecular mutation signatures in GBM also include the TP53 gene encoding the p53 protein, which is crucial indetermining cell fate in response to damages by arresting the cellcycle, triggering cell repair, or inducing apoptosis.8