KLK3 and prostate cancer: Several task forces have recommended against using PSA as ascreening test for prostate cancer.4 To help overcome the problem of false-positives, other markers have beenproposed, such as free PSA and human kallikrein-related peptidase 2 (hK2), amolecule similar to PSA5 but different in its enzymatic activity6 and beta-microseminoprotein (MSP).7