CHEK2 and cancer: These HR-DDR genes, including BRCA1, BRCA2, ATM, CHEK2, and Fanconi’s anemia genes (eg, FANCA, BRIP1), are associated with increased susceptibility to PARP inhibitors in various cancer types, such as breast, ovarian, prostate, and pancreatic cancers.48, 49, 50, 51, 52 PARP inhibitors have many potential mechanisms, but one way that the PARP inhibitor works is by tethering PARP complexes to unrepaired DNA ends, leading to cell death.53