The risk of breast cancer was highest for women with a pathogenic variant in BRCA1 or BRCA2: hazard ratio (HR) of 16.2 (95% CI: 10.9-24.1, P = 2.6e−76) for BRCA1 and HR = 8.5 (CI: 5.8-12.5, P = 1.3e−39) for BRCA2 (Figure 2A). Here, BRCA1 is linked to breast cancer.