KCNQ1 and KCNE1, subunits of the secretory K+ channel, were co-localized in the apical membrane of strial marginal cells; the Na+/2Cl-/K+ cotransporter SLC12A2, which is located in the basolateral membrane of strial marginal cells, was found in stria vascularis; and the gap junction protein GJB2 was found in spiral ligament of Slc26a4+/+ and Slc26a4-/- mice (Fig. 8).