NAC gets used by some CF patients to do topical lung treatments because people with CF have an excess of glutathione internally to their cells and a shortage on

NAC gets used by some CF patients to do topical lung treatments because people with CF have an excess of glutathione internally to their cells and a shortage on the surface, so they seek to address the surface shortage which is easier than figuring out what causes the imbalance and addressing that. My thinking is that cells hoard it internally to buffer against deadly chemical derangement, so it's of limited use to add more to the surface. It seems likely that cancer operates somewhat similarly.