In this post hoc analysis of a population-based diagnostic trial (STHLM3, n = 58 588), 4588 men aged 50–69 yr, without previous prostate cancer, with International Prostate Symptom Score (IPSS) data, and having PSA ≥ 3 ng/mL were identified. The gene discussed is KLK3; the disease is Familial prostate cancer.