TGFB1 and neoplasm: Over time, tumors develop immunosuppressive microenvironment features (30) (Figure 1A) such as altered expressions of receptors and ligands that activate or inhibit NK cells (18, 31, 32), the recruitment of immunomodulatory cells into the tumor mass (33), altered metabolism that results in lower oxygen and increased lactate (34, 35), and the production of inhibitory molecules including TGF-β, IL-10, PGE2, and immune checkpoint proteins such as PD-L1 (32, 36).