CFTR and cystic fibrosis: In 2019, the U.S. Food and Drug Administration (FDA) approved Trikafta (referred to as ETI hereafter), a combination of CFTR potentiator Ivacaftor (VX-770) and CFTR correctors Elexacaftor (VX-445) and Tezacaftor (VX-661), which provides benefits especially on the pulmonary functions to most CF patients including those of the F508del mutation (13).