PARP1 and ovarian carcinoma: UWB1.289, a BRCA1-null ovarian cancer cell line, displayed slightly higher basal PAR levels compared to UWB1.289+BRCA cells, which have restored BRCA1 function (Figure 2A), perhaps reflecting greater reliance on PARP activity for DNA damage repair in the HR-deficient UWB1.289 parental cells.