The physiological importance of secreting mucus with the correct properties is exemplified in the disease cystic fibrosis where the loss of a functional cystic fibrosis conductance regulator (CFTR) that transports chloride and bicarbonate results in mucus plugging in CFTR-expressing organs such as the airways, small intestine, pancreas, and reproductive tract, which in turn leads to inflammation, and subsequent organ damage [10]. This evidence concerns the gene CFTR and cystic fibrosis.