PARP1 and acute promyelocytic leukemia: However, PARP1 overexpression has been correlated with poor treatment response in children with acute lymphoblastic leukemia,19 while PARP1-driven apoptosis has been shown to be important in patients with chronic lymphocytic leukemia.20 Moreover, PARP1 inhibitors have been tested in vitro in hematologic malignancies, mostly lymphoid malignancies,21, 22 but also in AML, MDS and acute promyelocytic leukemia (APL).