CTLA4 and cancer: Immunotherapeutic strategies, including cancer vaccines, oncolytic viruses, adoptive transfer of ex vivo activated T and natural killer cells, and administration of antibodies or recombinant proteins, are now being described at a breathtaking pace, especially after the clinical application of the monoclonal antibody blocking of cytotoxic T lymphocyte-associated protein 4 (CTLA-4) and programmed cell death protein 1 (PD1) [102].