GJB2 and deafness: Previous studies found expression of Cx26 in the stria vascularis, spiral ligament, spiral limbus and supporting cells of the human cochlea (3) Among >100 deafness genes identified thus far, mutations in the gap junction protein Cx26, coded the by GJB2 gene, account for more than half of hereditary non-syndromic deafness in humans (4,5).