Similar selective killing by PARP1/2 inhibitors (PARPi) has also been observed in cancer cells with normal BRCA alleles, but that molecularly and clinically phenocopy BRCA loss – termed “BRCAness” – mediated through mutations in other HR repair genes, such as ATM, CHEK1, and RAD51, or the tumor suppressor PTEN [3, 11]. Here, PARP1 is linked to cancer.