When F508del-CFTR escapes ER quality control and reaches the PM, its open probability is reduced compared to wild-type CFTR and it is internalized more rapidly, which may place a ceiling on the efficacy of CF therapeutics, several of which [lumacaftor (VX-809), elexacaftor (VX-445) and tezacaftor (VX-661)] are used clinically (Van Goor et al., 2011; Keating et al., 2018). Here, CFTR is linked to cystic fibrosis.