CD4 and cytomegalovirus infection: If, as described in cytomegalovirus infection (Gamadia et al, 2003), the presence of interferon-γ-secreting CD4+ cells is essential for the development of mature and effective CD8 and B-cell responses, infusion of an mixed population of melanoma-reactive cells of both CD4+ and CD8+ phenotype may assist CD8+-cell survival and maturation and result in enhancement of a broad antimelanoma immune response.