CFTR and cystic fibrosis: Since European Medicines Agency (EMA) approved elexacaftor–tezacaftor–ivacaftor (ETI) for people with cystic fibrosis (PwCF) in 2020, the improvement in lung function and the decrease in sweat chloride have been superior to that demonstrated in PwCF treated with previous generations of cystic fibrosis transmembrane conductance regulator protein modulator (CFTRm) (1–3).