PARP1 and neoplasm: For example, better understanding of the contribution of the various mechanisms of action in vivo, in the context of different PARP inhibitors and different tumor types, together with better understanding of mechanisms of resistance will aid in improving the therapeutic potential of this class of drugs by optimizing patient selection (e.g., based on baseline or PARP inhibitor-mediated changes in HRD profile) or optimizing selection of therapeutic agents in combination clinical trials by targeting separate mechanisms of drug resistance.