This substantial upward shift in the risk of death at low PSA levels for older men results in a reduction in the overall increase in cancer death risk as PSA increases and may account for the reduction in the AUC for PSA alone as age increases with AUC of 0.77, 0.73, 0.71, and 0.71 for ages 50–59, 60–69, 70–79, and 80–89 years, respectively. The gene discussed is KLK3; the disease is cancer.