PARP2 and central nervous system cancer: When administered with 1 mM topotecan as well as irradiation, spheroids of U87 glioma cells showed radiation sensitivity of 1 mM.Reported lower selectivity for PARP-1 and PARP-2 than that of veliparib but greater than that of niraparib.In animal models, there is a high level of brain permeation