It is important to note that the long-term benefit of PSA testing is a 20% to 30% reduction in prostate cancer death.8,9,10 However, this benefit must be weighed against the harms of screening, which include false-positive test results, diagnostic uncertainty, overdetection, overtreatment, and adverse effects of both diagnostic and therapeutic procedures. This evidence concerns the gene KLK3 and prostate carcinoma.