Some studies suggest that depletion of PARG leads to PARPi resistance in BRCA2-deficient mouse mammary tumor models, which results in increased PAR levels even when PARP1 is largely or partially inhibited, thus counteracting PARP1 trapping and promoting PARPi resistance (Miwa et al., 1974) (Gogola et al., 2018). This evidence concerns the gene PARP1 and breast cancer.