Acute exposure of CLL cells to ibrutinib leads to a nearly complete loss of pAktS473 and stabilization of FoxO1 protein levels, which triggers transcription of FoxO1 targets such as Rictor, but possibly also FoxO1 itself (FoxO1 binds its own promotor; ref. 74). Here, RICTOR is linked to B-cell chronic lymphocytic leukemia.