Tumor cells express antigens that make them visible to the immune system. Nevertheless tumors escape the immune surveillance and grow by triggering mechanisms that promote immune tolerance. Cancer immunotherapy tries to reestablish the immune surveillance and counteract immune tolerance mechanisms to achieve clinical responses. In our laboratory, we are investigating mechanisms by which innate and adaptive effector T lymphocytes are recruited in the tumor immunesurveillance and strategies to harness their functions for the design of more efficacious immunotherapy.