TGFB1 and neoplasm: Immunosuppressive DCs can also be generated under tumor microenvironment-derived factors, such as β-catenin, indoleamine 2,3-dioxygenase (IDO), endoplasmic reticulum (ER) stress, lactate, vascular endothelial growth factor (VEGF), IL-10, TGF-β, prostaglandins, accumulation of adenosine, increased levels of lactate and hypoxia (38–42).