GJB2 and oculodentodigital dysplasia: Hyperactive hemichannels are associated with connexins and diseases, including keratitis-ichthyosis-deafness syndrome (MIM: 148210) (GJB2 [Cx26] [MIM: 121011]), Charcot–Marie–Tooth disease (MIM: 302800) (GJB1 [Cx32] [MIM: 304040]), oculodentodigital dysplasia (MIM: 164200) (GJA1 [Cx43] [MIM: 121014]), and cataract (MIM: 116200) (GJA8 [Cx50] [MIM: 600897]), although their etiologies are unknown [44–47].