To date, predictive clinical markers in prostate cancer are the prostatic acid phosphatase (Gutman et al. 1936; Yam, 1974; Vihko, 1979; Lin et al. 1980; Sakai et al. 1992; Veeramani et al. 2005) and serum PSA (Sensabaugh, 1978; Cooper et al. 1990; Grignon and Hammond, 1995; Schrohl et al. 2003; Veeramani et al. 2005). The gene discussed is KLK3; the disease is Familial prostate cancer.