Platelet factor 4 (PF4) is a small cytokine belonging to the CXC chemokine family that is also known as chemokine (C-X-C motif) ligand 4 (CXCL4) . This chemokine is released from alpha-granules of activated platelets during platelet aggregation, and promotes blood coagulation by moderating the effects of heparin-like molecules.
Platelet factor 4 (PF4) is a small protein released from platelets during platelet aggregation that helps regulate blood clotting by influencing the actions of heparin-like molecules.