It is unlikely that the associations seen between age, BMI, and PSA are solely the result of associations with prostate cancer, as the likelihood tests showed no evidence that the results from men with a PSA less than 3.0 ng/ml (not biopsied) were different from men with a PSA more than 3.0 ng/ml (biopsied). This evidence concerns the gene KLK3 and Familial prostate cancer.