Interferon-γ (IFN-γ) secreted by the infiltrated CD8+ T lymphocytes was required for CD274 induction, implying that upregulation of CD274 (PD-L1) within the tumor microenvironment served as a negative feedback mechanism, which represents a compensatory immune response by CD8+ T cells and IFN-γ within the tumor microenvironment4,9. The gene discussed is CD8A; the disease is neoplasm.