GJB2 and Hyperkeratosis: Altered epidermal proliferation and differentiation occur in K10Cx26 (D66H), Cre;Cx26+/floxS17F, Cx26-G45E, and pgk-Cre;Cx30+/floxA88V mice, which results in epidermal hyperplasia and hyperkeratosis [44,50,51].