Alcaligenes xilosoxidans 0 1 0 FEV 1 , forced expiratory volume in 1 second as % predicted. In 1 stable CF patient analysis of CFTR mutations is missing. Statistically significant differences between stable and acute CF patients are shown. 100nm identify exacerbations, and evaluate the efficacy of novel therapies [31] . Sputum is a rich, non-invasive source of biomarkers of inflammation and infection, and has been used extensively to assess inflammation in the CF airways (reviewed in [15] ). There is compelling evidence from small single-centre studies supporting an association between sputum biomarkers and disease status in CF.