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. Here, KLK3 is linked to Familial prostate cancer.