To activate the adaptive immune response to tumors [14], we detected the expression of CD11c, MHC II, CD86, CD4, CD8, and CD69 in mouse transplanted tumors by IHC and studied the infiltration and activation of DCs and CD4+ T, and CD8+ T cells in the tumor microenvironment after (−)-Guaiol intervention. The gene discussed is CD8A; the disease is neoplasm.