Glycosylation is a common type of post-translational modification (PTM) involving the covalent bonding of oligosaccharide chains to polypeptide chains. The synthesis pathway of mammalian glycans consists of 10 monosaccharide units: fucose (Fuc), galactose (Gal), glucose (Glc), N-acetylgalactosamine (GalNAc), N-acetylglucosamine (GlcNAc), glucuronic acid (GLCA), iduronic acid (IdoA), mannose (Man), sialic acid (SA), and xylose (Xyl).