RPS6KB1 and B-cell chronic lymphocytic leukemia: Specifically, GSK3β, constitutively active in resting cells, is inactivated through an inhibitory phosphorylation at Serine 9 (S9) by several pathways, including PI3K/AKT, PKA, PKC, p90RSK and p70S6K [25–27], with many of them which are aberrantly activated in CLL cells [2].