In this study, the results of the sphere formation assays, western blot analysis and flow cytometry analysis, which were employed to detect the self-renewal capacity, the expression levels of classical CSCs marker proteins (for example, CD133, SOX2, Nanog and Oct4) and the subpopulation of CD133+/CD44+ cells, showed that POS could significantly weaken CSCs stemness in GBM cells as evidence that POS is a potential CSCs-targeting antitumor drug for GBM treatment. This evidence concerns the gene POU5F1 and glioblastoma.