Much of the recent excitement in the translational field of tumor immunology and
immunotherapy has been generated by the recognition that immune checkpoint proteins can
be blocked by human antibodies with profound effects in vitro, in animal tumor systems, and
in patients. Promising clinical data have already been generated in melanoma and other
tumor types with human antibodies directed against cytotoxic T lymphocyte antigen-4 (CTLA-
4) and programmed death-1 (PD-1). The preclinical data that supported the clinical …