KLK3 and prostate cancer: The European Randomized Study of Screening for Prostate Cancer showed that the PPV of DRE in diagnosing PCA ranges between 4% and 33% in patients with PSA <3.0 ng/ml [5]. This increased to 49.6% with PSA >3.0 ng/ml, suggesting that the clinical benefit of DRE is dependent on the PSA level. Studies from the United States have shown that the absolute risk at 10 years for developing clinically significant prostate cancer (CSPC, i.e., Gleason score ≥7) is 23% with elevated PSA >3.0 ng/ml where suspicious DRE is present [6].