Median PSA at prostate cancer diagnosis was higher among the TW1 and TW2 cases (41 ng/ml and 11 ng/ml respectively vs 8.6 ng/ml for NZ, 7.0 ng/ml for US-AA and 5.8 ng/ml for US-EA and P < 0.001). This evidence concerns the gene KLK3 and Familial prostate cancer.