IL6 and cystic fibrosis: To conclude, our results suggest that the presence of exacerbations, non-nasal S. aureus carriage, female gender, the presence of S. aureus SCVs, co-infection with S. maltophilia or specific anti-staphylococcal IgG- and IL-6 levels are independent risk factors for worse lung function in CF patients with persistent S. aureus infection.