Men who had a father or brother with prostate cancer were twice as likely to have ever had a PSA test (OR = 1.92, 95% CI 1.86–2.00) compared to men with no family history; whilst men who had a father and a brother with prostate cancer were more than five times as likely (OR = 5.32, 95% CI 4.13–6.85, p-value for linear trend <0.001). Here, KLK3 is linked to prostate carcinoma.