CFTR and cystic fibrosis: Importantly, treatment of CF cells with the small molecules VX-809 and 4,6,4’-trimethylangelicin (TMA), which act as ‘correctors’ for F508del CFTR by increasing the amount of functional CFTR at the cell surface and rescuing the F508del CFTR-dependent chloride secretion [61,62] (see above, Section 2.2.2), significantly improved all the mitochondrial parameters towards values found in the airway cells expressing wildtype CFTR, strongly suggesting that the restorative action provided by the correctors on mitochondrial functions in CF cells is linked to the rescue of chloride channel activity.