1. Tagami H (2002) What is the ‘true’ function of skin. Viewpoint 9. Exp Dermatol 11:180–182
2. Elias PM, Feingold KR, Fluhr JW (2003) Skin as an organ of protection. In: Freedberg IM, Eisen AZ, Wolff K, Austen KF, Goldsmith LA, Katz S, Fitzpatrick TB (eds) Fitzpatrick's dermatology in general medicine, 6th edn. McGraw Hill, New York, pp 107–118
3. Schaefer H, Redelmaier TE (1996) Skin barrier: principles of percutaneous absorption. Karger, Basel
4. Hirao T, Denda M, Takahashi M (2001) Identification of immature cornified envelopes in the barrier-impaired epidermis by characterization of their hydrophobicity and antige-nicity of the components. Exp Dermatol 10:35–44
5. Kobayashi H, Tagami H (2004) Functional properties of the surface of the vermilion border of the lips are distinct from those of the facial skin. Br J Dermatol 150:563–567