The cleaved peptide of PAR1 is a more potent stimulant of platelet-endothelial cell adhesion than is thrombin.
Claytor RB, Michelson AD, Li JM, Frelinger AL, Rohrer MJ, Garnette CS, Barnard MR, Krueger LA, Furman MI. The cleaved peptide of PAR1 is a more potent stimulant of platelet-endothelial cell adhesion than is thrombin. J Vasc Surg. 2003 Feb; 37(2):440-5.