In another study by Zhou et al., also conducted on an American population, the most significant factors associated with greater PCa-specific mortality were three: (1) Prostate-specific antigen (PSA) doubling time of less than 3 months following radical prostatectomy (HR, 54.9; 95% CI: 16.7–180), (2) a PSA doubling time of less than 3 months following radiotherapy (HR, 12.8; 95% CI: 7.0–23.1), and (3) a biopsy Gleason score of 8–10, which represents the histological grade (HR, 6.1; 95% CI: 3.4–10.7)27. Here, KLK3 is linked to posterior cortical atrophy.