CFTR and cystic fibrosis: ELEXA/TEZA/IVA (ETI) treatment increased the CFTR-mediated anion secretion to Isc values that became indistinguishable from non-CF samples mostly to S737F/Dele22-24 genotype (Isc values means moved to 98% and 62% of non-CF mean for S737F/W1282X and S737F/Dele22-24, respectively).