In the absence of widespread access to a substantially improved treatment for early prostate cancer in the last 15 years of the 20th century, it seems most likely that the extremely rapid improvement in recorded survival for men diagnosed with prostate cancer during the period 1986–1999 reflects an increase in the diagnosis, treatment and registration of men with asymptomatic malignancy as a result of the increasingly widespread use of PSA tests during the 1990s (Evans and Møller, 2003). This evidence concerns the gene KLK3 and prostate cancer.