KLK3 and prostate carcinoma: Prostate cancer diagnosis and staging involve taking a comprehensive history, performing a digital rectal examination (DRE), measuring serum prostate-specific antigen (PSA), performing transrectal ultrasound (TRUS)-guided prostate biopsy, and performing histological grading using Gleason or International Society of Urological Pathology (ISUP) score [1-22].