CD274 and neoplasm: To address the last part of this model, we again performed IFN-γ ELISPOT assays on CD8 T cells isolated from mice treated with 500 cGy WBI and combined checkpoint blockade, but anti–PD-L1 or control IgG1 antibody was also added in vitro to the 48-hour CD8 T cell/tumor cell co-cultures.