MDSC is an important component of TME and can perform immune suppressive function via various mechanisms, namely, producing nitric oxide (NO), reactive oxygen species (ROS) and mostly anti-inflammatory cytokines such as IL-10 and TGF-β, eliminating key nutrition factors which are vital to T cell proliferation, and preventing CD8+ T cell from entering the tumor region (32, 33). This evidence concerns the gene TGFB1 and neoplasm.