LETTERS TO THE EDITOR 1425 activity than the recently identified pendrin inhibitors,
PDSinh-A01 and PDSinh-C01 (see Fig E1, DI). 6 YS-01 inhibited both human and mouse
pendrin-mediated Cl 2/I 2 exchange with nearly identical potency (see Fig E2, A and B, in
this article's Online Repository at www. jacionline. org). YS-01 weakly inhibited Cl 2/HCO3 2
exchange activities of SCL26A3 and SLC26A6 with IC50 greater than 100 mM and did not
affect SCL26A7 and SLC26A9. Cystic fibrosis transmembrane conductance regulator …