Diagnosis of prostate cancer involves a multi-faceted approach incorporating PSA levels, positive imaging findings (e.g., multiparametric magnetic resonance imaging (MRI), prostate-specific membrane antigen (PSMA) positron emission tomography (PET) scan), and histopathological confirmation via either transperineal or transrectal biopsy of the prostate gland. This evidence concerns the gene KLK3 and prostate cancer.