A series of enzymatic substitutions modifies the basic structure of complex-type biantennary N-glycans. Among them, a b1,2-linked N-ace-tylglucosamine residue is introduced to the central mannose moiety of the core-fucosylated oligosaccharide by N-acetylglucosaminyltransferase VII. This so-called LEC14 epitope can undergo galactosylation at theb1,2-linked N-acetylglucosamine residue.