ABSTRACT
As long ago as the mid-1970s, Elias et al. [1] discovered that the intercellular lipidlike substance of the stratum corneum, which acts as a sort of cement between the corneocytes, has a lamellar structure. The compound system formed by the dead cells and the lamellae is the skin's actual barrier against the environment. Some years later, the same work group [2] became aware of the relatively high proportion of ceramides besides cholesterol, free fatty acids, and triacylglycerol in the intercellular lipid layer. The cerarnides are credited with playing an important role in the lamellar lipid structure and in the barrier function of the stratum corneum.
