To date, neither the prostate specific antigen (PSA) test [3] nor the digital rectal examination is 100% accurate, and because of overdiagnosis of prostate cancer (which can be as high as 80% [4]), since 2012, the U.S. Preventive Services Task Force (USPSTF) has no longer recommended PSA testing as a routine screening test for all men over the age of 50 [5]. This evidence concerns the gene KLK3 and prostate cancer.