CD34 and leukemia: Activated in human CD34+ cells after transduction with BCR–ABL1, dependent on Tyr177, PI3K inhibitor effective in p210 human CD34+ in vivo model (39, 40), Ph+ ALL mouse model, and Ph+ ALL patient cells (41). Akt activation plays a role in steroid resistance (55). Pi3K inhibitors in trials for relapsed leukemia: BKM120, BEZ235, AMG319, idelasilib