CFTR and cystic fibrosis: Further treatment with the new and highly effective modulator combination, VX-661 (3 μM), VX-445 (3 μM) and VX-770 (1 μM) (TRIKAFTATM) [24], restored F508del-CFTR function to approximately 50% of Wt-CFTR function of non-CF HIOs (Figure 4b–d).