KLK3 and prostate carcinoma: The main tests used for prostate cancer detection, such as digital rectum examination (DRE) and prostate-specific antigen (PSA), present flawed diagnoses, particularly among patients who have PSA of between 4 and 10 ng/ml, with a false negative rate of 20 to 30%.2,3 Therefore, the method of choice for obtaining a conclusive diagnosis is transrectal ultrasound (TRUS) guided prostate biopsy.2–4 However, the possibility that prostate cancer is present is not totally excluded even with a negative result.