Treatment with T-VEC was found to decrease the levels of suppressor cell populations, including CD4+Tregs, CD8+T suppressor cells, and MDSCs, in injected lesions compared with non-injected lesions in the same (and different) melanoma patients, whereas in parallel this treatment increased the levels of local and systemic MART-1-specific CD8+effector cells in tumors undergoing regression compared with melanoma patients not treated with OV. This evidence concerns the gene CD4 and melanoma.