CFTR and cystic fibrosis: Proteins like myeloperoxidase, IL-8, cleaved alpha-antitrypsin, and S100A8 (or CF antigen), have been found in sputum as predictors of pulmonary exacerbations [6], or associated with the presence of CFTR mutations [7], [8], in addition to proteomic signatures in serum corresponding to inflammation markers [9].