For the carriers of the XPD-751 Gln/Gln genotype, a similar increase in the risk of breast cancer was seen for women smoking ≥10 cigarettes/day (OR 4.78, 95% CI 1.50–15.2) while no statistically significant increase was seen by smoking years (OR 2.25, 95% CI 0.85–5.96 for women smoking ≥15 years), compared to women smoking the same amount, but not carrying the homozygous variant XPD-751 Gln/Gln genotype. Here, ERCC2 is linked to breast cancer.