Currently, alpha-fetoprotein (AFP) for liver cancer (Liu et al., 2017), prostate-specific antigen (PSA) for prostate cancer (Wilt and Dahm, 2015), and carcinoembryonic antigen (CEA) for colon cancer (Konishi et al., 2018) are all glycosylated proteins that have been used as biomarkers in clinical application. This evidence concerns the gene KLK3 and colonic neoplasm.