Cystic fibrosis (CF) is the most common life-threatening autosomal recessive genetic disease among Caucasians worldwide, and is caused by mutations in a single gene encoding an epithelial chloride channel, the phosphorylation-activated cystic fibrosis transmembrane conductance regulator (CFTR), that result in decreased channel expression and/or function1–3. This evidence concerns the gene CFTR and cystic fibrosis.