In vivo studies demonstrated that the NP vaccine could induce a strong, antigen-specific, in vivo cytotoxic T lymphocyte response against 4T1 breast cancer cells; and that combination immunotherapy of the vaccine and anti-CTLA-4 monoclonal antibody could significantly enhance anti-tumor immune response compared to the vaccine or monoclonal antibody alone (175). The gene discussed is CTLA4; the disease is neoplasm.