CFTR and cystic fibrosis: Alongside CFTR-mediated ion channel disturbance in CF, a number of studies have reported dysregulated or excessive apoptosis in CF epithelial cells following external stimuli [61, 94]; a recent report shows that, under basal conditions, Fas expression was increased in epithelial cell lines leading to increased activation of caspases-3 and -8 and subsequent apoptosis.