The most important function of the skin is the formation of a barrier between the “inside” and
the “outside” of the organism, which prevents invasion of pathogens and fends off chemical
assaults as well as the unregulated loss of water and solutes. The physical barrier is mainly
localized in the stratum corneum, which consists of protein-enriched cells and lipid-enriched
intercellular domains. Any modifications in epidermal differentiation and lipid composition
results in altered barrier function, a central event in various skin alterations and diseases …