EGFR and glioblastoma: The most common mutations identified were TERT promoter (TERTp), CDKN2A/B, NF1, PTEN, TP53, and EGFR. Global analysis of metabolites shows a statistically significant difference in CSF metabolite levels between patients with TP53-wildtype and TP53-mutant GBM (Fig. 4), as well as PTEN-mutant and PTEN-wildtype GBM (Fig. 5).