Adaphostin induces apoptosis in CLL B cells. (A) Western blot analysis for PARP cleavage, cleaved caspase-3, and levels of antiapoptotic proteins (Bcl-2, Mcl-1, XIAP, survivin) at increasing doses of adaphostin. (B) Western blot analysis demonstrating the timing of PARP cleavage in CLL B cells exposed to 2.5 μM adaphostin. C indicates control treated cells; A, adaphostin-treated cells (2.5 μM). PARP cleavage became evident in this experiment at 48 hours, coinciding with the onset of cell death as seen in Figure 1D.