Although single knockout or knockdown of S6K1 or S6K2 was insufficient to entirely reduce rpS6 phosphorylation, the combination of S6K1 and S6K2 inactivation cooperated to substantially reduce rpS6 phosphorylation, consistent with overlapping and compensatory functions in GBM (Fig. 4A–C). This evidence concerns the gene RPS6KB2 and glioblastoma.