This book is about the phenotypic and functional features of epidermal Langerhans cells in experimental models and in clinical medicine. Langerhans cells, members of the dendritic cell system in the skin, are critically involved in the regulation of cell-mediated immune responses and gain increasing attention in a wide spectrum of clinical areas such as allergy, autoimmunity, transplantation and resistance to tumors and infections. The book covers the latest, most timely developments in this rapidly advancing field. Leading researchers describe functional analyses at the cell and molecular level, elucidating processes related to antigen presentation and the role of cytokines, and discuss perspectives for a future use of Langerhans cells and other dendritic cells in the immunotherapy of various diseases.