CD8A and neoplasm: Supporting this assertion, numerous studies involving various cancers have associated patient response to treatment with the selective expansion and activation of antigen-specific CD8+ CTLs, reduced Treg cell activity, IFN-γ secretion and expression of IFN-γ-inducible genes, and subsequent IFN-γ-induced upregulation of PD-L1 expression on both tumor cells and TILs [9, 69–75].