Men with localized prostate cancer (PCa) are categorized in risk groups that reflect increasing treatment failure rates and prostate cancer specific mortality (e.g. low, intermediate or high) on the basis of pathologic Gleason score (GS), pre-treatment serum prostate specific antigen (PSA, measured in ng/mL) and clinical T-category (TNM staging system) [1-2]. This evidence concerns the gene KLK3 and prostate cancer.