Description: CD230 (prion protein; PrPC) is a 35 kD glycoprotein, attached to the cell surface via a GPI-anchor. While the function of CD230 is unclear, prion protein has been the focus of research based on its involvement in transmissible spongiform encephalopathies (TSE), including Creutzfeld-Jakob disease in humans. CD230 undergoes a conformational change in which the cellular PrPC form is converted to the scrapie PrPSc form. This conversion is essential for the infectiousness of prion-based diseases. CD230 is predominantly expressed on the surface of lymphocytes and monocytes, with weak expression on granulocytes and erythrocytes. In platelets, CD230 is expressed primarily intracellularly, and is upregulated to the surface upon activation.