CLDN6 and dermatitis: In contrast, apparently normal prenatal epidermal development and formation of a functioning EPB, but an abnormal postnatal lifelong keratinocyte hyperproliferation leading to progressive thickening of the epidermis - but no dermatitis, results when a mutant form of Cldn6 lacking its entire tail domain (Inv-Cldn6-CΔ187) is expressed [17].