That FoxO proteins positively regulate stem cell marker expression in the GBM-SCs studied by us was confirmed using a synthetic inhibitor of FoxO1/3 transcriptional activity, and by FoxO3 overexpression which inhibited the loss of stemness proteins upon γIR/PI-103 treatment in p53-proficient GBM-SCs. This evidence concerns the gene GPR83 and glioblastoma.