Accumulating studies indicated the value of glycosylation in disease diagnosis and prognosis.367 A variety of glycoproteins have been used as tumor markers in clinical diagnoses and predictor activities, such as alpha-fetoprotein in liver cancer, prostate-specific antigen (PSA) in prostate cancer, or glycol-residue-related markers, such as CA19-9 in pancreatic cancer.241,368. The gene discussed is KLK3; the disease is liver cancer.