PARP1 and acute myeloid leukemia: A similar enhanced effect on penfluridol-induced caspase-3 activation and PARP cleavage was induced by another antioxidant, GSH (Fig. 4d), suggesting that ROS production might play a protective role in the penfluridol-induced apoptotic effect in AML cells harboring FLT3-WT and FLT3-ITD.