Platelets, by interacting with cancer cells in the bloodstream and by the release of lipid mediators (i.e., TXA2 and 12-HETE) and growth factors, including platelet-derived growth factor (PDGF) and transforming growth factor (TGF)β, may induce in cancer cells epithelial–mesenchymal transition (EMT) and the COX-2-signaling pathway, typically associated with a metastatic phenotype [249,250,251]. This evidence concerns the gene TGFB1 and cancer.