Dendritic cells (DCs) are a vital component of the immune system. Their main function is to detect the presence of pathogens and act as antigen presenting cells, processing antigenic material then presenting it on their surface in the context of major histocompatibility complex (MHC) molecules to lymphocytes. Thus DCs provide a crucial link between innate and adaptive immunity. DCs efficiently activate naive T cells making it particularly important that they are correctly targeted by vaccines in order to induce both effector and memory responses. This property of DCs has important clinical application in the development of cancer vaccines. However, under certain circumstances DCs can also tolerize T cells, exploiting this may lead to the development of novel therapies for T-cell mediated autoimmune diseases. Recently, there has been substantial progress in the understanding of how to manipulate DCs, however the challenge of translating this from experimental models into the clinic remains. Some patents on DCs, which may lead to the development of effective immunotherapy, are discussed in this review.