Much of the excess incidence in economically developed regions, along with the rapid rise in prostate cancer incidence in the early 1990s, is attributed to the widespread practice of prostate-specific antigen (PSA) testing to detect asymptomatic tumors, many of which are clinically indolent and would not otherwise become clinically apparent [35, 36]. This evidence concerns the gene KLK3 and Familial prostate cancer.