With a normal DRE finding, the five groups with PSA levels of less than 4.0, 4.0 to 10.0, 10.0 to 20.0, 20.0 to 100.0, and ≥ 100.0 ng/ml had the cancer detection rates of 29.7, 13.5, 25.6, 55.6, and 0%, respectively. This evidence concerns the gene KLK3 and cancer.