If the current tested cases and controls cohorts have sufficiently represented the general NZ, US and TW men, the current findings pose the question of validity of the age-based PSA thresholds to be used in prostate cancer screening of all US-EA men or the specific AKR1C3 rs12529 genotype stratified groups in NZ, US-AA, and TW men. This evidence concerns the gene KLK3 and prostate carcinoma.