Thus, although the introduction of ETI in the clinical arena is very recent, it seems well established that the majority of treated patients will obtain relevant benefit from ETI therapy; however, as variability is expected in both effects on CFTR function and clinical status, long-term studies will allow to better define the mechanisms and the clinical impact of this therapy, and in particular its role in modulating CF airway infections. The gene discussed is CFTR; the disease is cystic fibrosis.