CFTR and cystic fibrosis: In the lungs, dysregulation of ion transport by the defective CFTR protein leads to the build-up of thick secretions and a subsequent pro-inflammatory response.8 These thick secretions provide a favourable environment for chronic microbial colonisation by pathogens such as Pseudomonas aeruginosa and Aspergillus fumigatus, which represent risk factors for lung pathology and hospital admission.9 10 Repeated exacerbations of lung disease and eventual decline in overall lung function are common in CF.