CTLA4 and neoplasm: Taken together, the mixed preclinical and clinical data employing local ablative RT with OX40 agonistic antibody, systemic IL-2, or anti-CTLA-4 antibody demonstrate that signaling through CD25 and OX40 reciprocally reinforce each other to augment effector cell priming initiated by local RT and improve the quality and magnitude of T cell responses against tumor-associated antigens.