PARP1 and leukemia: After the evaluation about the potential activity of ALT in imatinib-sensitive and -resistant cells, Wei et al. have concluded that ALT treatment contributes to significant cell apoptosis in both imatinib-sensitive and -resistant leukemia cells, as indicated by the increase of caspases activation and poly (ADP-ribose) polymerase-1 (PARP-1) cleavage (Wei et al., 2013).