Recruitment of leukocytes to the growing thrombus. Leukocyte recruitment to the thrombus is influenced by the condition of the endothelium and the shear rate in the vessel. (A) Under low shear with intact endothelium, leukocytes are able to bind adhesive molecules on the endothelial surface such as VWF, selectin family members, and cell adhesion molecules to leukocyte-expressed PSGL-1 or integrin receptors. (B) In arterial thrombosis, leukocyte recruitment to the thrombus is influenced by platelet binding, where glycoprotein receptors/β1 and β3 integrins on activated platelets bind to subendothelial adhesion molecules such as VWF, collagen, laminin, and fibronectin. Leukocytes bind to adhered platelets in a PSGL-1/P-selectin–dependent manner and are further stabilized by additional ligand-receptor interactions. EMMPRIN, extracellular matrix metalloproteinase inducer; JAM-3, junctional adhesion molecule; LFA-1, lymphocyte function-associated antigen 1.