These include immunosuppressive cytokines such as IL-10 and TGF-β; expression of indoleamine-2,3-dioxygenase; the presence of myeloid-derived suppressor cells (MDSCs) and regulatory T cells (Tregs); inhibitory ligands such as B7-H1/PD-L1; and the dense tumor stroma that is characteristic of this disease [40,41]. This evidence concerns the gene CD274 and neoplasm.