PARP1 and triple-negative breast carcinoma: Although levels of PARP1 expression and/or activity are generally reported to be higher in tumor cell lines than in normal cells [15], [16] and in several primary tumor types, including triple-negative breast cancer, than in syngeneic nonmalignant tissue [17], comparisons of PARP activity or PAR levels in PBMCs to that in tumor tissue are not abundant.