PARP1 and neoplasm: We therefore applied an integrated MS-based functional proteomics approach including chemical proteomics, phosphoproteomics, and ADP-ribosylation proteomics to characterize PARP1 protein complexes across BRCA1-deficient and BRCA1-proficient OC cell lines and patient tumor specimens and to determine the proteome-wide effects of PARPis on OC cell signaling pathways.