RPS6KB1 and cancer: Specifically, the lentivirus-packed constitutively-active mutant Akt (S473D), caAkt1 [18, 44, 48], was stably transduced to pCan1 primary cancer cells, which completely restored Akt and S6K1 phosphorylation in SKI-178 (10 μM)-treated cells (Fig. 6B).