Interestingly, addition of anti-PD-1 antibody to radiation significantly induced tumor-infiltrating CD8+ effector cells not only in irradiated tumors but also in out-of-field tumors, leading to the regression of both irradiated and out-of-field tumors [40], although the mechanism of how tumor-infiltrating lymphocytes were recruited to the out-of-field tumor remains unclear. The gene discussed is CD8A; the disease is neoplasm.