For example, it is quite common to see over-utilization of expensive, invasive, and/or high technology interventions, such as percutaneous transluminal coronary angioplasty (PTCA) [92], and screening for prostate cancer with prostate specific antigen (PSA) assays [93,94], without convincing evidence of the effectiveness of these interventions. The gene discussed is KLK3; the disease is prostate cancer.