However, there was a significant difference when comparing GBM cases with high ID4, SOX4 and OCT-4 expressions (median survival of 6 months) with cases with low expressions for the three genes (median survival of 18 months) (log rank p = 0.014), as shown on the Kaplan-Meier survival curve in Figure 6. This evidence concerns the gene POU5F1 and glioblastoma.