Neutrophilic inflammation has been implicated in COPD pathology (56, 57) and in elastase-induced emphysema (41, 42), and previous studies of allergic airways disease have linked DUOX1 to production of neutrophil chemokines (CXCL1) and neutrophil recruitment (53, 58). This evidence concerns the gene CXCL1 and pulmonary emphysema.