In the lungs of infants with CF, mucus plaque formation (composed predominantly of MUC5AC and MUC5B) can be seen in greater numbers compared with non-CF pulmonary infection and closely correlates with neutrophilic inflammation and associated products of necrosis such as neutrophil extracellular traps (NETs) [53]. This evidence concerns the gene MUC5AC and cystic fibrosis.