Platelet activation with a PAR1 agonist triggered TGF-β secretion, which induced EMT of SW620 human colon cancer cells via the downregulation of miR-200b expression, and activated platelets had a chemotactic effect on colon cancer cells mediated by the upregulation of CXCR4 on the cell surface. The gene discussed is CXCR4; the disease is colonic neoplasm.