As we could not discriminate the induction of each ACE2 isoform individually in the analysis performed in vivo, we measured the levels of ACE2 (all isoforms), flACE2, dACE2 and ISG15 after ex vivo stimulation with IFNβ in cells collected from oropharyngeal swabs of CF individuals and healthy donors. Here, ISG15 is linked to cystic fibrosis.