It is interesting to note that K6- and K17-positive suprabasal cells, which are normally not present in the mature epidermis except in situations of abnormal cell proliferation and differentiation [25]–[27], are not detectable in the interfollicular epidermis of either the juvenile or aged Inv-Cldn6-CΔ196 transgenic samples, until patent dermatitis is evident (see below). This evidence concerns the gene CLDN6 and dermatitis.