CD4 and neoplasm: Interferon-gamma (IFNγ)-producing CD4+ T helper (Th1) cells are highly efficient antitumoral players because of their ability to induce polarization into proinflammatory M1 macrophages, cross-prime CTLs, initiate the recruitment of dendritic and natural killer (NK) cells 16, 19-22, or induce tumor senescence 23.