Langerhans cells are antigen-presenting cells that play a key role in the initiation and regulation of immune response. They are localized in stratified epithelia, such as epidermis, and migrate to the lymphoid organs in order to present antigens introduced in the skin so that the T cell response can be initiated. Light and electron microscopy images of the cells demonstrate their morphology within the epidermis and as they migrate to the culture medium. Factors inducing migration are reviewed, as well as the therapeutic potential of these factors in regulating the immune response.