CFTR and cystic fibrosis: Current pharmacological strategies to rescue and/or improve CFTR function in CF focus on i) the development of CFTR correctors that increase the number of apical membrane CFTR Cl− channels by improving the processing or synthesis of mutant CFTR; and ii) the development of potentiators that improve the open probability (PO) of mutant CFTR Cl−channels that are delivered to the cell surface, but exhibit impaired gating [3], [10].