Fig. 4. Depletion of survivin expression potentiates TRAIL-mediated apoptosis. H1299 cells were transiently transfected with scrambled negative siRNA (Scram) or survivin specific siRNA (siSurvi). After three days, the cells were treated with TRAIL (20 ng/ml) for 10 hours. Then cell death was determined with Annexin V/PI staining (A). The cells were then harvested, and subjected to Western blot analysis with the indicated antibodies (B), (n=3, *<0.05).