TGF-β/SMAD mediates the exosomal secretion of CXCL12/CXCR4 chemokines by CAFs, where CXCL12 promotes cancer malignancy by increasing tumor cell proliferation, migration, and angiogenesis (Kuzet and Gaggioli, 2016). The gene discussed is TGFB1; the disease is neoplasm.