KLK3 and prostate cancer: Around 20–30% is produced by the prostate, it contains zinc (Zn) in large quantities, which has antibacterial properties, and has a role in the coagulation of semen along with zinc-binding proteins like seminogelin I. Prostate specific antigen (PSA) is another zinc-binding protein with a proteolytic effect responsible for the colliquation of semen, with widely known clinical importance in the screening and diagnosis of prostate cancer.