When we analyzed only patients > 65 years of age with a serum ferritin level > 400 ng/ml, we found increased sensitivity in terms of diagnosing prostate cancer using total PSA (AUC = 0.89) or [log (total PSA)*(serum ferritin)] (AUC = 0.90) (Figure 1B). This evidence concerns the gene KLK3 and prostate cancer.