In contrast, when cancer-cell-derived exosomes are taken up by monocytes, the effects of TGF-β and prostaglandin E2 contained in the exosomes induce the differentiation of monocytes into bone-marrow-derived immunosuppressive cells, which release various immunosuppressive molecules such as IL-10, thereby promoting the inactivation of immunocompetent cells and the induction of regulatory T cells to suppress anti-tumour immunity [345]. This evidence concerns the gene TGFB1 and cancer.