The Fascinating Story That Began in 1868. Origin, Cell Lineage, Ontogeny, Tissue Distribution, and Kinetics of Langerhans Cells. Identification and Phenotype of Epidermal Langerhans Cells. Structural Organization and Biological Properties of Langerhans Cells. Enrichment of Epidermal Langerhans Cells. Langerhans Cells as Antigen-Presenting Cells. Langerhans Cells as Immature Dendritic Cells. Epidermal Cell Derived Secretory Regulins. The Influence of Ultraviolet Radiation and Other Physical and Chemical Agents on Epidermal Langerhans Cells. Tolerizing Versus Sensitizing Signals Derived from the Epidermis. Role of Langerhans Cells in Disease. Index.