F2RL2 (PAR3) is a member of the protease-activated receptor (PAR) family of G protein-coupled cell surface receptors. F2RL2 is a cofactor in the thrombin-mediated cleavage and activation of the protease-activated receptor family member PAR4. It is essential for hemostasis and thrombosis, and is involved in inflammation and chronic inflammatory diseases. Cathepsin G activation of platelets is also dependent on F2RL2. In immunohistochemistry, F2RL2 has highest membranous positivity on megakaryocytes in bone marrow (with lower positivity in mature megakaryocytes), on patelets, and in other tissues including the heart, gut, retina and brain. References: Thrombosis J 17, 4 (2019). DOI:10.1186/s12959-019-0194-8