Murine tumor-derived Tp53-/-Brca2-/- KB2P3.4 cells and Brca2-reconstituted Tp53-/-Brca2IBAC KB2P3.4R3 cells35 were treated with the PARP inhibitor olaparib, and libraries were prepared for Strand-seq analysis (Fig. 1A). Here, PARP1 is linked to neoplasm.