A) Cohorts of 6 NSG mice were xenografted with MV4;11 cells expressing BimS ligand variants under doxycycline control. Doxycycline water was fed to mice from day 5+ and survival assessed. B. Cohorts of 6 NSG mice were xenografted with MV4;11 cells expressing BimS2A under doxycycline control. Mice were allocated to treatment with either vehicle or ABT-199 on days 5-12 +/- doxycycline water from day 5+ and survival assessed. All mice in the arm combining Doxycycline (to suppress Mcl-1) and ABT-199 (to target Bcl-2) were alive and leukemia-free on day 100.