XRCC1 and cancer: To the best of our knowledge, however, this is the first study to investigate the association between in vitro BPDE-induced adducts and polymorphisms of the BER genes (XRCC1, PARP1, and APEX1), in which the APEX1 Asp148Glu polymorphism was shown to modulate levels of BPDE-induced DNA adducts, suggesting that APEX1 Asp148Glu may be one of the underlying mechanisms for the observed low host’s DRC involved in cancer susceptibility in the general population.