“…The continued development of efficacious CFTR modulators requires a better understanding of the function of this channel. The modulators from Vertex, although highly efficacious, do not impact all patients with eligible CFTR genotypes, nor do they solve all of the problems in this multiple organ system disease or lead to long-term stabilization of lung function ( Flume et al, 2018 ; Gauthier et al, 2020 ; Guimbellot et al, 2017 ; Konstan et al, 2017 ; Li et al, 2019 ; McKinzie et al, 2017 ; Moheet et al, 2021 ; Patel et al, 2020 ; Phuan et al, 2018 ), revealing a need to continue to study CFTR to develop new therapies ( Davies et al, 2019 ; Grand et al, 2021 ; Veit et al, 2018 ). Understanding the nature of the stable open state may aid in the rational design of drugs that can lock mutant CFTR channels open, leading to increased Cl − secretion and amelioration of CF disease and potentially some forms of chronic obstructive pulmonary disease and other lung disorders ( Raju et al, 2016 ; Solomon et al, 2016a ; Solomon et al, 2016b ).…”