This result, taken together with the Ussing chamber experiments in which Eso did not change either Fsk-or UTP induced Isc (Figure 6C), suggests that Eso does not increase ASL pH in CF hAECs via an increase in either mutant CFTR, or calcium-mediated anion secretion, but rather, it works via inhibiting proton secretion. The gene discussed is CFTR; the disease is cystic fibrosis.