The immunosuppressive effects of MDSCs are primarily mediated through the production of inhibitory molecules such as arginase‐1, inducible nitric oxide synthase (iNOS), and reactive oxygen species (ROS), as well as the secretion of immunosuppressive cytokines including IL‐10 and TGF‐β, which collectively inhibit the anti‐tumor functions of T cells and natural killer cells. The gene discussed is TGFB1; the disease is neoplasm.