To study the swelling of human intestinal organoids in response to different plasma levels of new mutation-targetted drugs; to correlate the entity of the swelling with the respiratory function test variations; to investigate the reproducibility of results in cryopreserved samples. Drugs active on specific mutations in the CFTR gene will be tested: Ataluren, ivacaftor and the combination of ivacaftor and lumacaftor. The model of organoids would thus be fully exploited for prediction of clinical response and monitoring of established therapies in individual patients.