Compared with PSA screening alone, using the S3M test at a reflex threshold of ≥ 1.5 ng/mL was predicted to reduce the lifetime number of screening tests by 3%, diagnostic biopsies by 28% and prostate cancers diagnosed during a man’s lifetime by 1%, with 4 additional QALYs and, conversely, 3 additional prostate cancer deaths per 10,000. Here, KLK3 is linked to prostate cancer.