KLK3 and prostate cancer: The emergence of molecular technologies has also led to a variety of developments in the area of secondary cancer prevention, as proteinic biomarkers of effect (biomarkers associated with possible or established disease) are being widely used to screen for cancer, including prostate-specific antigen (PSA) screening for prostate cancer, cancer antigen 125 (CA125) screening for ovarian cancer and human papillomavirus (HPV) screening for cervical cancer.1