This study included 42 269 individuals with invasive cancer and known ER status (23 353 [55.2%] had a known intrinsic-like subtype) and 71 072 control patients from 31 studies participating in the Breast Cancer Association Consortium.23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52 The mean (SD) age of all participants was 57.9 (10.9) years, and women were predominantly of European ancestry (approximatively 84%). This evidence concerns the gene ESR1 and breast cancer.