p66Shc deficiency impinges on the BCL2 family balance (Figure 2), shifting the ratio of BCL2 family members towards the pro-survival BCL2/BCL2L1, to the detriment of the pro-apoptotic BAK/BAX in the p66Shc-deficient CLL B cells [13] as well as in leukemic cells from Eμ-TCL1 mice [52]. This evidence concerns the gene BAK1 and B-cell chronic lymphocytic leukemia.