We enroled 25 pwCF, mean age 9.1(6.3) years, all carrying 2 CF causing variants of the CFTR gene (11 homozygous p.Phe508del (F508del thereafter); 7 F508del compound heterozygotes; 7 carrying nonsense, splicing mutations or large deletion variants) (Table 1). Here, CFTR is linked to cystic fibrosis.