TGFB1 and neoplasm: Tumor-derived exosomes were found to convert conventional CD4+CD25neg T cells into a potent suppressive population of CD4+CD25hi Foxp3+ Tregs, with increased expression of TGF-β, IL-10, CTLA-4, and enhanced suppressive activity against effector responses, which can be reversed through the inhibition of TGF-β or IL-10 (72, 73).