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 and 2–11 year old children showed correlations of the change in cAMP-mediated and cholinergic chloride secretory response with the age of people with CF (P < 0.01 and P < 0.05, respectively). This evidence concerns the gene CFTR and cystic fibrosis.