Cancer immunotherapy is designed to specifically target cancer types using components of the immune system. Therefore DNA vaccines are also faced many obstacles that include breaking peripheral T cell tolerance against tumor self-antigens, to elicit appropriate immune reactions, as well as overcoming tumor-derived immunosuppressive networks and evasion tactics. Evasive mechanisms adopted by malignant cells to prevent immune cell function are numerous and lead to the clonal expansion of non-immunogenic tumor cells, by loss of tumor antigen, and to the apoptosis prevention [35] .