CFTR and cystic fibrosis: Low levels of mitochondrial reduced glutathione (mtGSH) and defects in GSH transport have been found in CF patient-derived airway cells and in CFTR-knockout, resulting in an altered extracellular ratio between reduced and oxidized GSH (Gao et al., 1999; Velsor et al., 2006; Kelly-Aubert et al., 2011).