XIAP and acute lymphoblastic leukemia: Xie et al. had recently reported that the potent, selective and orally bioavailable BCL-2 inhibitor ABT-199 (Venetoclax), in combination with the potent CDK9 inhibitor CDKI-73 (LS-007) synergistically induced apoptosis in the acute leukemia (AML and ALL) cell lines HL-60, CCRF-CEM and Molt-4, accompanied by increased PARP and Caspase-3 cleavages and reduction in XIAP and MCL-1 expression [153].