In the COGS, analyses had been conducted on 46,785 breast cancer cases and 42,892 controls to estimate breast cancer risk overall, 27,078 ER-positive cases and 42,111 controls for ER-positive breast cancer risk, and 7,333 ER-negative cases and 42,468 controls for ER-negative breast cancer risk18. Here, ESR1 is linked to breast carcinoma.