CD8A and neoplasm: Addition of a PD-L1 inhibitor has been shown to reverse RT-induced tumor equilibrium in favor of tumor regression in mice subcutaneously injected with melanoma and breast tumors demonstrating RT-induced stable disease (SD, defined as ≥3 weeks) characterized by a transient rise and fall in levels of tumor-infiltrating CD8+ T-cells and IFNγ [92].