CFTR and cystic fibrosis: To test the hypothesis that the response to CFTR modulator therapy is age-dependent, we performed a secondary analysis of the ICM data of our previous studies on the effects of lumacaftor/ivacaftor on CFTR function in F508del homozygous people with CF aged 12 years and older (Graeber et al., 2018) and 2–11 year old children (Berges et al., 2023).