IFNG and cystic fibrosis: CF/Intermittent-Free PA patients had significantly better lung function than CF/Chronic PA patients (S6 Fig.), and when both groups of CF patients were analysed separately, the correlation between IFN-γ production in response to PHA and lung function only remained significant in the case of CF/Chronic PA patients (Fig. 2B; S7 Fig.) (CF/Chronic PA patients, IFN-γ vs. FEV1 (L): r = 0.6484, p = 0.0144; IFN-γ vs. % predicted FEV1: r = 0.6201, p = 0.0157).