With these two variables we were able to identify 17% of the cohort for which the Gleason score was⩽5 and PSA<25 ng ml−1 or the Gleason score was 6 and PSA⩽4 ng ml−1 where prostate cancer mortality at 10 years was less than 10% and 33% of the cohort with Gleason score 7 and PSA>25 ng ml−1, or Gleason score 8 and PSA>10 ng ml−1, or Gleason score⩾9 where prostate cancer mortality at 10 years was greater than 30%. The gene discussed is KLK3; the disease is Familial prostate cancer.