Immunosuppressive cells and inhibitory factors are important components of the tumor immunosuppressive microenvironment, and include regulatory T cells (Tregs), marrow-derived suppressive cells (MDSCs), tumor-associated macrophages (TAMs), interleukin-10 (IL-10), and transforming growth factor (TGF-β). The gene discussed is TGFB1; the disease is neoplasm.