Innate and adaptive immunity play important roles in immunosurveillance and tumor destruction. However, increasing evidence suggests that tumor-infiltrating immune cells may have a dual function: inhibiting or promoting tumor growth and progression. Although regulatory T (Treg) cells induce immune tolerance by suppressing host immune responses against self- or non self-antigens, thus playing critical roles in preventing autoimmune diseases, they might inhibit antitumor immunity and promote tumor growth. Recent studies demonstrate that elevated proportions of Treg cells are present in various types of cancers and suppress antitumor immunity. Furthermore, tumor-specific Treg cells can inhibit immune responses only when they are exposed to antigens presented by tumor cells. Therefore, Treg cells at tumor sites have detrimental effects on immunotherapy directed to cancer.

Introduction.- The role of NKT cells in the immune regulation of neoplastic disease.- ¿¿ T Cells in Cancer.- Toll-like receptors and their regulatory mechanisms.- Cytoplasmic sensing of viral double-stranded RNA and activation of innate immunity by RIG-I-Like Receptors.- Innate immune signaling and negative regulators in cancer.- Dendritic Cell Subsets and Immune Regulation.- Human Dendritic Cells in Cancer.- Regulatory T cells in cancer.- Relationship between Th17 and regulatory T cells in the tumor environment.- Mechanisms and control of regulatory T cells in cancer.- Myeloid Derived Suppressor Cells in Cancer.- Myeloid Derived Suppressor Cells and Treg cells in Tumor Microenvironment.- Cell Surface Co-Signaling Molecules in the Control of Innate and Adaptive Cancer Immunity.- Negative regulators of NF-¿B activation and type I interferon pathways.- Role of TGF-ß in immune suppression and inflammation.- Indoleamine 2,3-dioxygenase and tumor-induced immune suppression.- Myeloid-Derived Suppressor Cells in Cancer:  Mechanisms and Therapeutic Perspectives.- Human tumor antigens recognized by T cells and their implications for cancer immunotherapy.- Cancer/testis (CT) Antigens: Potential Targets for Immunotherapy.- Tumor antigens and Immune Regulation in Cancer Immunotherapy.- Immunotherapy of Cancer.- Current Progress in Adoptive T-Cell Therapy of Lymphoma.- Adoptive Immunotherapy of Melanoma.- Index.