The prostate-specific-antigen (PSA) blood test was originally approved by the US-Food-and-Drug-Administration in 1986 to monitor the progression of prostate cancer in men who had already been diagnosed with the disease (2) As a screening-test for men from the age-of-50-years, the PSA-blood-test in conjunction with the digital-rectal-exam has also received support from Medical-Benefit-Schemes and was routinely recommended from 1994 to 2008 (2). Here, KLK3 is linked to prostate cancer.