ABCB1 and cancer: In this study, we selected six previously studied SNPs, located either on the protein coding regions or in regulatory regions of the genes, including ERCC1 rs11615, XPD/ERCC2 rs13181 and breast cancer susceptibility gene 1 (BRCA1) rs1799966 from the NER pathway; XRCC1 rs25487 from the BER pathway, XRCC3 rs1799794 from the DSBR pathway, as well as MDR1/ABCB1 rs1045642 (Table S1).