ERCC6 and breast cancer: Joint effect analysis revealed increased risk of breast cancer with the ERCC8 1/1 and ERCC6 2/5 diplotype combination (OR 3.03, 95% CI 1.16–7.91, p = 0.024) and the ERCC8 1/1 and ERCC6 1/6 diplotype combination (OR 3.27, 95% CI 1.17, 9.18, p = 0.024) compared with the reference category (Table 2A).