P-Selectin, also known as CD62P, Granule Membrane Protein 140 (GMP-140), and Platelet Activation-Dependent Granule to External Membrane Protein (PADGEM), is a cell surface glycoprotein that plays a critical role in the migration of lymphocytes into tissues. P-Selectin consists of an EGF-like domain, an NH2-terminal lectin type C domain, a transmembrane domain, a short cytoplasmic domain, and nine complement control domains. Evidence indicates that P-Selectin is mobilized to the cell surface in response to a variety of inflammatory or thrombogenic agents.Circulating soluble P-Selectin is slightly smaller than native P-Selectin. Evidence suggests that the majority of sP-Selectin lacks the transmembrane anchoring domain due to its alternatively spliced mRNA. Monitoring of sP-Selectin levels in serum provides more detailed insights in several pathological situations such as thrombotic thrombocytopenic purpura and haemolytic uremic syndrome.