A review. On first sight, a statement like Nobel laureate Ralph Steinman life and death were intricately connected with dendritic cells may sound trivial or superfluous. However, it isn't Ralph Steinman and Zanvil Cohn detected dendritic cells (DC) in 1973 (Steinman and Cohn, 1973). It took him and his group at Rockefeller University the following decade to provide evidence that DC are the pivotal and only cell type to activate an immune response against pathogens, i.e., viruses, bacteria, fungi and parasites. However,in a special edition of Scientific American published in 1993, DC are only marginally mentioned macrophages were still described as the principal activators of immunity against pathogens. DC are patrolling the body regions where infectious agents (viruses, bacteria, fungi and parasites) are most likely to enter the skin, airways, intestines and genitals. DC have a pivotal role for the innate and adaptive immune responses in a dual mode of action (Fig. 18.1). Once activated through their sentinel and sensor functions, DC secrete cytokines of the type I interferon family, which in turn upregu- Iate responder cells to secrete other cytokines and chemokines. In one branch of the dual modes, the genuine signaling pathway upregulates proliferation and activation of innate effector killer cells, i.e., natural killer cells (NK cells) and natural killer T cells (NKT cells). The other branch of the bifurcated pathway leads to the maturation of DC into professional antigen-presenting cells (APC). Antibodies bind to and tag their specific antigen targets on the surface of pathogens or tumor cells such tagged targets are then destroyed by effector cells of the innate immune system (NK cells and NKT cells) which had been activated by DC in the corresponding innate immune response. Here in this review we discuss on the therapeutic potential of dendritic cells.