In addition, we adopted a sphere formation assay to detect the self-renewal capacity, performed western blotting to measure cancer stem-like cells (CSCs) marker proteins (CD133, SOX2, Nanog and Oct4) and applied flow cytometry to monitor the subpopulation of CD144+/CD33+ cells, and the results all demonstrated that POS can remarkably weaken CSCs stemness. This evidence concerns the gene NANOG and cancer.