The tetra-antennary N-glycan reduced the adhesion of TBCF10839 to the CF mucin from donor 2 and the adhesion of CF1-10 to the CF mucin from donor 4 suggesting that the two CF isolates do not only recognize O-glycans, but also bind to the asparagine-linked complex-type oligosaccharides of N-glycosylproteins. This evidence concerns the gene MUC5AC and cystic fibrosis.