PARP1 and cancer: Importantly, chemotherapy programs should focus on precision therapy, meaning that therapy with inhibitors associated with DNA damage repair defects should be employed with consideration of the cancer patient’s traits, such as genetic background, environment, lifestyle, diet, culture and race, which are important factors that can affect therapy results.502 Finally, chemotherapy resistance is a serious threat to the fight against cancer, and the mechanisms underlying resistance, such as that reported for PARP-1 inhibitor resistance, require further elucidation.