To further investigate the mechanism of sFn inhibition of monocyte/tumor cells adherence, four peptides were chosen which had previously been reported to represent major fibrin(ogen) binding sites on CD54 (P1) and αMβ2 (P2) for fibrin(ogen), and the fibrin(ogen) γ-chain binding sites for CD54 (P3) or αMβ2 (P4). This evidence concerns the gene SFN and neoplasm.