In fact, data from the Cancer of the Prostate Strategic Urologic Research Endeavor (CaPSURE), an observational database of prostate cancer patients from 35 US centres, on 2078 cases diagnosed between 1989 and 2001 with low-risk prostate cancer (serum PSA </=10 ng ml−1, Gleason sum </=6 and clinical T stage </=T2a), show that just 7.9% of such men chose an observation policy, rather than treatment (Cooperberg et al, 2004). The gene discussed is KLK3; the disease is prostate cancer.