BRCA1 and breast cancer: They utilized data from 15,252 female BRCA1 PV carriers (BC = 7797, OC = 2462) and found strong associations between the PRS and BC and OC risk (particularly, the PRS for ER-negative BC displayed the strongest association with BC risk with a hazard ratio (HR)  =  1.27, 95% CI = 1.23–1.31, p  =  8.2 × 10−53).