CHEK2 and breast cancer: The OR for the top PRS3820 decile (1.9, 95% CI 1.7–2.1) was slightly lower than that of the moderate-risk BC genes ATM (OR 2.5, 95% CI 1.7–3.9) and CHEK2 (OR 2.1, 95% CI: 1.5–3), but still in a similar range.