Indeed, an initial preclinical study showed that combining RT (1–2 fractions of 12 Gray (Gy) to the primary tumor) with an anti-cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) monoclonal antibody resulted in synergistic antitumor activity in a poorly immunogenic metastatic mammary carcinoma mouse model when CTLA-4 blockade by itself was ineffective [54]. This evidence concerns the gene CTLA4 and neoplasm.