CSF2 and melanoma: T reg, CD8+ T cells and CD4+ effector memory T cells had significantly increased proliferation demonstrating the initiation of a T cell-mediated immune response within the TDLN. In addition, memory T cells were able to activate naïve T cells in the TDLN for a sustained immune response. This CD4+ T cell subset was also found in the peripheral blood of patients with melanoma responding to anti-CTLA-4 + GM-CSF therapy.