According to the GLOBOCAN reports, there were about 12.7 million cancer cases and 7.6 million cancer deaths in 2008, and the cancer burden continues to increase worldwide [1]. At present, the common treatments for cancer include surgery, chemotherapy, radiotherapy, and immunotherapy. Immunotherapy aims to enhance or regulate the patient’s own immune response to fight against tumors. It represents a novel and effective strategy in cancer treatments, but, generally, its efficacy needs to be improved [2]. Cancer vaccination is an important and promising approach in cancer immunotherapy. For many years, prophylactic vaccines have exhibited profound accomplishment in preventing serious infectious diseases in humankind, including polio, small pox, and diphtheria. However, cancer vaccines are vastly different from the prophylactic vaccines in that they are aimed to eliminate preexisting tumors. Furthermore, the immune system is immunosuppressed in most cancer patients, so it is much more difficult to develop effective cancer vaccines.

In 1973, Dr. Steinman first discovered a novel type of cell,“dendritic cell (DC)”[3]. Later on, Steinman and other immunologists demonstrated that DCs are professional antigen-presenting cells (APCs) and they play critical roles in the activation of antigen specific naïve T cells; therefore, tumor antigen-pulsed DCs are believed to boost acquired immune response effectively in vivo to eradicate tumors. In 1992, Dr. Steinman and Dr. Inaba established a method for generating large numbers of DCs in vitro [4]. The method dramatically promoted experimental studies on DC biology and their applications in clinical research, and in the year of 1996, Hsu et al. published the first clinical study on DC vaccines in B cell lymphoma patients. In this study, all the four patients developed measurable antitumor immune