KLK3 and prostate cancer: Importantly, increased PSA is a strong predictor of aggressive prostate cancer (Carter et al., 1992, Catalona et al., 2000, Schröder et al., 2012, MacKintosh et al., 2016;6:157-, Loeb et al., 2012)and about 90% of prostate cancer deaths occur among men with PSA > 2 ng/ mL at age 60 (Carlsson et al., 2014, Cuzick et al., 2014).