In response to IFNγ release by CD8+ T cells and NK cells, tumor cells activate JAK–STAT signaling and up-regulate immunosuppressive proteins, such as PD-L1 and IDO [60,61] (Fig 2A), which support cancer cell resistance to cytotoxic killing by both T cells and NK cells [60–62]. The gene discussed is CD8A; the disease is neoplasm.