BCL2 and leukemia: Western blot revealed that Bim−/− Eμ-Tcl1 Tg leukemias exhibited comparable levels of Bid, Puma, Bcl-2 and Bcl-XL expression to their Bim+/+ counterparts (Supplementary Figure 9a) indicating that compensatory changes in expression of activator BH3-only proteins, or pro-survival molecules, had not occurred and that the tumors did not display stabilizing p53 mutations.