This includes over-expression of immune checkpoint ligands (such as PD-L1 or Gal-9) by blasts themselves, but also the presence of various regulatory cells, such as CD4+ regulatory T cells (Tregs), Myeloid-Derived Suppressive Cells (MDSC), or tumor-associated macrophages (TAM), which inhibit the immune response through a number of mechanisms such as production of Indole-amine 2,3 dioxygenase (IDO), TGFbeta, arginase, IL-10, among many other immunosuppressive factors (90, 91). The gene discussed is CD274; the disease is neoplasm.