CAF-derived exosomal microRNA (miR)-17-5p caused CRC cells to secrete TGF-β1 into the TME through RUNX3/MYC/TGF-β1 signaling, which triggered CAFs to release more exosomal miR-17-5p to CRC cells, thus establishing a positive feedback loop for CRC metastasis [120]. The gene discussed is TGFB1; the disease is colorectal carcinoma.