To examine whether CD4+ and CD8+ T cells were infiltrated in tumors that produced chemokines is consistent with the ability of effector cells and molecules to play a role in tumor regression mechanisms, we assessed the infiltration of CD4+ and CD8+ T cells, as well as expression of IFN-γ related chemokines (CXCL9 and CXCL10) in established MCA304 tumors of mice receiving the IL-13Rα2 DNA and boost vaccination. The gene discussed is CD4; the disease is neoplasm.