[Comment] Relationship between CFTR variants, sweat chloride responses, and lung function improvements

Cystic fibrosis, the most common autosomal-recessive lung disease, was a deadly disease in infancy or early childhood for many centuries. Over the past seven to eight decades, symptomatic therapies have improved quality of life and reduced morbidity and mortality, thereby slowly increasing life expectancy to adulthood. Malfunction of the cystic fibrosis transmembrane conductance regulator (CFTR) protein underlies cystic fibrosis. The introduction of CFTR modulator therapies, small molecules that improve the function of the CFTR protein, changed the face of cystic fibrosis to an unprecedented degree.