Indeed, when loss of ZEB1 expression was stratified with CD133 expression (Fig. 5a, hazard ratio 1.73, 0.95% CI, 1.28–2.34; **P = 0.0003) the result was shortened patient survival, suggesting that the effect of ZEB1 loss on survival was consistent with an increase in the proportion of the glioma stem cell population in the tumor. This evidence concerns the gene PROM1 and central nervous system cancer.