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Communication between cells as a prerequisite for life of multicellular organisms is achieved mostly by solvent mediators like hormons, neurotransmitters, cytokines and chemokines. Increasing evidence suggests that a class of cytokines exists that signals from immune cells specifically towards epithelial cells. The most prominent member of these "tissue-signaling cytokines" is Interleukin-17 (IL-17). This book illustrates IL-17 is essential to protect the human organism at its skin surface against invading microorganisms. Cellular sources of IL-17 and trigger factors of IL-17 secretion in the skin are defined. Finally, this book identifies two human diseases associated with chronic infections of the skin that are at least partially caused by a disturbed IL-17 pathway - the orphan syndrome "chronic mucocutaneous candidiasis" and the very common inflammatory skin disease "atopic dermatitis/ eczema".

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Dr.Dr. Kilian Eyerich, born in 1979, studied human medicine inWürzburg and Munich. In 2006, he started his medical career asdermatologist at the Technical University Munich, intermitted byresearch stays in Rome and London. In 2010, he awarded the titlePhD. For his research activities on the skin immune system, hewon several prices and grants.

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