ENaCs can help compensate for broken chloride channels
They found that there were indeed gene variants that could explain why these patients were able to live longer with better lung function. These particular coding regions were responsible for the production of epithelial sodium channels, or ENaCs. ENaCs are proteins that are responsible for cellular pathways that help the kidney, colon, lung, and sweat glands reabsorb sodium.
In cystic fibrosis, the mutation classically involves the chloride channel preventing rehydration of lung airways and pancreatic ducts. What scientists hypothesize is that this ENaC channel can step in and help to rehydrate these structure when this chloride channel is malfunctioning. If this is true, it could explain why patients with a variant in the ENaC gene could potentially help compensate for the dysfunction we see in cystic fibrosis.