The European Randomized Study of Screening for Prostate Cancer (ERSPC) and Prostate, Lung, Colorectal and Ovarian (PLCO) cancer screening trials have indicated that PSA levels in men 55 to 74 years old are ≥ 3.0 ng/mL in approximately 14–16% [20]. " Here, KLK3 is linked to Familial prostate cancer.