As the protein levels or activities of PARP1 are closely associated with cellular sensitivity to PARP inhibitors [7, 24–28] and RNF144A regulates PARP1 protein abundance (Figures 3 and 4), we next examined whether RNF144A could influence the sensitivity of breast cancer cells to PARP inhibitor olaparib [20], an FDA-approved targeted therapy for human cancers. Here, PARP1 is linked to breast cancer.