CD4 and melanoma: Inhibition of CD4+ T cell proliferation in the presence of melanoma cell lines resulted significantly lower in naïve cells (% of inhibition ± SD: 5.82 ± 5.04) than in effector memory (37.42 ± 14.86, p = 0.0048) and central memory (25.17 ± 5.7, p = 0.0079) CD4+ T cells (Figure 4, panel A).