KLK3 and prostate cancer: Exemplarily, the alpha-fetoprotein (AFP), carbohydrate antigen 125 (CA125), carbohydrate antigen 19-9 (CA 19-9), prostate-specific antigen (PSA), and carcinoembryonic antigen (CEA) biomarkers help to diagnose hepatocellular cancer, ovarian cancer, pancreas cancer, prostate cancer, and colon cancer respectively [3].