During the past 10 years, important progress has been made in the field of immunology, leading to a better notion of the relationship between the immune system and disease. While new immunotherapeutic efforts pave the way for the treatment of old diseases, understanding the biology, function and mechanisms of immune cell populations is of utmost concern for the development and optimisation of cellular immune therapies for the induction of effective immune responses in cancer and chronic infections on the one hand, and for the induction of T cell tolerance in autoimmune disorders and transplantation on the other hand. With the data presented in this book, we believe to have contributed to the knowledge on the role of immune effector cells, such as dendritic cells, in maintaining the subtle balance between immunity and tolerance. The data presented clearly open up new avenues in order to improve dendritic cell-based immunotherapies for immune stimulation and tolerance and should beespecially usefull to professionals in immunology or anyone else interested in cell-based therapies.