The distortion of blood vessels and high growth rate of tumor cells cause hypoxia in TME that mediates an immunosuppressive environment, characterized by an increase in the accumulation of immunosuppressive cells, including regulatory T cells (Tregs) and myeloid-derived suppressor cells (MDSCs), as well as secretion of a number of factors including vascular endothelial growth factor (VEGF) and transforming growth factor β (TGF-β). Here, TGFB1 is linked to neoplasm.