Source:http://linkedlifedata.com/resource/umls/id/C0376322
GO: A protein modification process that results in the addition of a sugar unit to a protein amino acid, e.g. the addition of glycan chains to proteins. [GOC:curators],NCI: The covalent chemical or post-translational biochemical addition of carbohydrate or glycosyl groups to peptides or proteins by glycosyl transferases.