In this secondary analysis of a cohort of 10 968 men aged 55 to 60 years who were enrolled in the screening group of the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial, baseline prostate-specific antigen levels were associated with any future prostate cancer and clinically significant prostate cancer diagnoses. The gene discussed is KLK3; the disease is Familial prostate cancer.