BIRC5 and leukemia: BIBR1532 impacts on cell survival also through the down-regulation of Survivin in leukemia cells, although through unknown mechanisms (37, 38); our results suggest that Survivin cooperated in inducing apoptosis in SCCF1 and SCCF2 but not in SCCF3, where Caspase 3 cleavage and subsequent apoptosis at 100 μM might instead be due to the activation of alternative cell death mechanisms triggered by telomerase deprivation, such as the extrinsic pathway (48).