In this context, the widely used prostate specific antigen (PSA) biomarker, tested in an equally heterogenous human population, was originally introduced with a predictive value of 28–35%[34] based on the rationale that there was no other minimally invasive option for early detection of prostate cancer at that time, which is true for CAN today. The gene discussed is KLK3; the disease is Familial prostate cancer.