• cystic fibrosis
• heterozygotes

In August 2015, Archivist reported on trials of what are now known as CFTR modulator drugs, which offer new hope for treating and preventing the progression of cystic fibrosis (CF) (doi:10.1136/archdischild-2015–309089). These drugs work at an intracellular molecular level, and can improve deficient functioning of the abnormal CFTR protein. Among other things they can improve chloride transport across the respiratory epithelial cell membrane, and hence reduce the problematic viscosity of mucus.

Which drug works depends on what CF mutation the patient has. The 2015 trials reported the first successes in this approach for the majority of patients who have the the …