Significantly increased CD8+ and CD4+ T-cells were detected at the melanoma injection site even though tumor cells were no longer observed, compared with contralateral brain parenchyma and naïve mice (for CD8+, injection site: 101±7.0 cells per 20X field, for contralateral brain: 2.0±0.5, and naïve mice: 24±6.6; for CD4+, injection site: 150±8.7 cells per 20X field, for contralateral brain: 1.1±0.67, and naïve mice: 48±18; mean±SE, n≥3). The gene discussed is CD4; the disease is neoplasm.