CFTR and pulmonary emphysema: Similarly, more recent studies demonstrated that the smoke-induced accumulation of ceramide was associated with the inhibition of CFTR expression and the severity of emphysema in COPD patients, in whom the CS-induced ceramide accumulation mediated the pathogenesis of COPD through a mechanism by activating NF-κB signaling and inducing epithelial cell apoptosis [17, 27, 33].