OCLN and atopic eczema: Molecularly, reduced expression of E-cadherin (CDH1), an adherens junction protein known to regulate tight junctions (Tunggal et al., 2005), and of the tight junction protein claudin 1 (CLDN1), which is crucial for the maintenance of the inside-outside barrier (Furuse et al., 2002) and has been found downregulated in atopic dermatitis patients (De Benedetto et al., 2011) was still evident at P3 in Δ/Δep2 epidermis, while occludin expression was normal (OCLN) (Figure 4C).