Flow cytometric analysis of bronchoalveolar lavage fluid showed an increased proportion and absolute number of neutrophils in the airways at 3 weeks post infection in CFTR-/- compared to WT controls (Fig 1J–1K, p ≤ 0.05) Alveolar macrophages were significantly delayed in returning to baseline numbers (Fig 1L, p ≤ 0.05), whereas neutrophils were still significantly increased in CFTR-/- airways at three weeks compared to controls where they returned to baseline numbers (Fig 1M, p ≤ 0.05). Here, CFTR is linked to infection.