SLC26A4 and bacterial infectious disease: Over the last decade the anion exchanger pendrin (PDS, SLC26A4), once thought to be limited mainly to the inner ear, kidney, and thyroid, has been found to be upregulated by inflammatory cytokines in the bronchial epithelium, where it contributes to the pathogenesis of inflammatory airway diseases [53–55] and also to the host response to bacterial infections [56, 57].