PCSK9 and breast cancer: LDL-raising variants in PCSK9 were associated with increased risk of breast cancer (OR 1.10, 95% CI, 1.02–1.19, P = 0.014) but not with ER-positive (OR 1.08, 95% CI, 0.99–1.18, P = 0.099) or ER-negative breast cancer (OR 1.13, 95% CI, 0.98–1.30, P = 0.089) at the nominal significance level (Fig. 3, Supplementary Table 7).