Fig 5, S5 Table demonstrates that VX-809 (3 μM) alone and in combination with VX-770 (5 μM) for 48 hours stimulated F508del-CFTR Cl secretion, although Cl secretion was less in CF-HBE cells treated with VX809 + VX-770 compared with cells treated for 48 hrs. with VX-809 alone. Interestingly, F508del-CFTR Cl secretion was not significantly reduced by VX-770 in CFBE cells treated with VX-809. However, in both CFBE cells and in CF-HBE cells treated with VX-809 + VX-770, P. aeruginosa (PAO1 and PA14) reduced F508del-CFTR Cl secretion (Fig 5, S5 Table). This evidence concerns the gene CFTR and cystic fibrosis.