Cystic fibrosis transmembrane conductance regulator (CFTR) potentiator. Corrects gating defects of CFTR mutants such as ΔF508 (Ka = 0.3 μM), E193K and G970R (Kd values are 0.22 μM and 0.45 μM respectively). Increases ΔF508-CFTR Cl- currents in the presence of forskolin; displays no effect on Ca2+-activated Cl- current.