KLK3 and posterior cortical atrophy: Although free prostate-specific antigen (fPSA), total prostate-specific antigen (tPSA), and the ratio of free PSA to total PSA (f/tPSA) are frequently applied to clinical PCa detection and grading indicators, (7–9), which indicators are more appropriate for the diagnosis and classification of PCa remains a controversy, and no agreement has been reached (10, 11).