A Danish cohort study of 29,875 women found both road traffic and railway noise to be associated with a higher risk of estrogen-receptor negative but not with estrogen-receptor positive breast cancer [137], which was partly supported by a large German case-control study (≈478,000 women) that indicated associations between exposure to high levels of aircraft noise only among women with estrogen-receptor negative breast cancer [141]. This evidence concerns the gene ESR1 and breast carcinoma.