PCSK9 and prostate cancer: MR results provided evidence of an effect of lower levels of circulating PCSK9 protein on overall prostate cancer (OR = 0.93, 95% CI = 0.87 to 0.997, P = 0.040, per SD reduction in plasma PCSK9 levels), and early-onset prostate cancer (OR = 0.86, 95% CI = 0.74 to 0.98, P = 0.030) but not advanced prostate cancer (OR = 0.98, 95% CI = 0.89 to 1.07, P = 0.600) using the IVW method accounting for genetic correlation structure, consistent with findings from our initial analyses.