In addition, in vitro cultures of CD4+ and CD8+ T cells purified from the spleens of the immunized and unimmunized mice revealed significantly increased activities of CD8+ T cells from the immunized mice to secrete GzmB, a key cytotoxic molecule for the cytotoxic activity of the T cells and IFN-γ in response to MC38 tumor cells. The gene discussed is CD8A; the disease is neoplasm.