PCa can be examined using several methods, including (1) digital rectal examination (DRE), which is the most straightforward and effective method, and critical for the diagnosis; (2) prostate-specific antigen (PSA) test, including total PSA and free PSA; (3) non-invasive ultrasound examination of the prostate, which can detect early internal nodular changes; (4) Computed Tomography (CT) examination of prostate lesions; (5) magnetic resonance examination of prostate lesions; and (6) prostate biopsy, usually performed with transrectal ultrasound guidance. Here, KLK3 is linked to posterior cortical atrophy.