HBE: human bronchial epithelial. ^#: patients that have the G551D mutation on at least one allele (the “x” stands for the G551D mutation or any other class I–V mutation [23]); ^¶: absolute change in FEV₁ % pred from baseline through week 16 between ivacaftor and placebo groups (the observed change was not statistically significant) [60]; ⁺: sweat chloride reduction in the ivacaftor versus placebo groups from baseline through week 16 [60]; ^§: increase from baseline in FEV₁ % pred through week 48 in the ivacaftor group compared with placebo [23]; ^ƒ: sweat chloride reduction in the ivacaftor versus placebo groups from baseline through week 48 [23]; ^##: mean percentage change from baseline in FEV₁ % pred at day 28 for a 200 mg dose [61]; ^¶¶: mean treatment difference in sweat chloride from baseline (−placebo) at day 28 for a 200 mg dose [61]; ⁺⁺: treatment difference obtained from the pooled data of two phase 3 pivotal studies for the average absolute change from baseline in FEV₁ % pred at week 16 and 24 (dose: lumacaftor 600 mg/ivacaftor 250 mg) [58]; ^§§: treatment difference in sweat chloride from a phase 2 trial for the lumacaftor 600 mg once daily/ivacaftor 250 mg once every 12 h homozygous group compared with the pooled combination placebo group in the mean absolute change from baseline at day 56 [58].