PTEN and glioblastoma: The overall survival of GBM patients grouped according to the expression of the signature based on the negative z-score of the mean gene expression (including NCOA4, NBN, STAG2, MAPRE1, E2F5, PTEN, and CEP57) is statistically significantly different with a hazard rate of 0.61 (95% confidence interval: 0.5–0.75), as shown in Figure 5, panel a.