Ten trials were included for analysis (European Randomised Study of Screening for Prostate Cancer; Cluster randomised trial of prostate-specific antigen (PSA) testing for Prostate cancer; Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial; Prostate Cancer Early Detection Study Based on a “Baseline” PSA value in Young Men; Göteborg-2; Early Prostate Cancer Detection Programme; Organised Prostate cancer Testing; STHLM3-MRI; ProScreen; and BARCODE1). The gene discussed is KLK3; the disease is ovarian cancer.