Up to now, although prostate specific antigen (PSA), a prostate specific, but not a prostate cancer specific expressed gene, is still the most widely used biomarker to screen prostate cancer, it is not an optimal biomarker to early diagnose of prostate cancer as well as its metastasis due to its limited sensitivity and specificity 5, 6. The gene discussed is KLK3; the disease is prostate carcinoma.