PARP1 and neoplasm: BMN 673, the most potent PARP inhibitor in clinical development, exhibits (i) high efficiency at killing tumor cells in vitro, possibly by effectively trapping PARP–DNA complexes (Shen et al., 2013 ▶; Murai et al., 2014 ▶), and (ii) impressive antitumor activity with limited toxicity in BRCA-deficient breast and ovarian cancer patients, and also early-stage clinical efficacy in a subset of small-cell lung cancer patients (Wainberg et al., 2013 ▶).