BCL2 and neoplasm: Because CTLs primarily cause tumor cell death via the induction of apoptosis, we chose to explore whether non-overlapping modalities using BH3 mimetics (activators of intrinsic apoptosis through inhibition of BCL-2 family anti-apoptotic proteins) and CTLs (primarily extrinsic apoptosis activators) can lead to enhanced anti-leukemic activity through apoptotic pathway crosstalk in which both the intrinsic and extrinsic apoptotic pathways are activated in the same tumor cell (18–20).