TP53 and glioblastoma: When stratifying patients into four subgroups based on p53 and PIK3R2 status (p53-negative/PIK3R2-negative, p53-positive/PIK3R2-positive, p53-negative/PIK3R2-positive, and p53-positive/PIK3R2-negative), a significant improvement in OS was observed in the p53-negative/PIK3R2-negative group both in GBM/Astro cases and GBM cases.