In APEX1 rs3136817, we found that the heterozygous TC genotype and the C allele were associated with breast cancer risk (adjusted OR = 0.670, 95% CI: 0.513 - 0.873, P = 0.003; adjusted OR = 0.729, 95% CI: 0.576 - 0.923, P = 0.009, respectively). This evidence concerns the gene APEX1 and breast cancer.