CD4 and melanoma: Applying an adenovirus vector encoding IL-12 in combination with the administration of a hydrophobic TGF-β inhibitor intratumorally with a multifunctional polymer significantly increased the frequency of CD4+ and CD8+ T cells, NK cells as well as IFN-γ secretion in the tumor microenvironment, which delayed growth of B16 melanoma xenografts in mice and increased animal survival [66].