KLK3 and prostate cancer: The main tests used for early prostate cancer detection are (1) digital rectum examination (DRE) and (2) prostate-specific antigen (PSA); the first is a subjective and examiner-dependent test, and the second is not always correlated with prostate malignancy [2–4], so the method of choice for a conclusive diagnosis is transrectal ultrasound guided prostate biopsy, with a rising concern regarding its collateral effects and complications nowadays [5].