{"type":"root","children":[{"type":"paragraph","children":[{"type":"text","value":"The protein encoded by CD63 gene is a member of the transmembrane-4 superfamily, also known as the tetraspanin family, and mediates signal-transduction events that play a role in the regulation of cell development, activation, growth and motility. This encoded protein is a cell-surface glycoprotein that is known to complexes with integrins. It may function as a blood-platelet activation marker. CD63 antibodyreacts with a 53 kDa protein. The antigen was originally designated as a lysosomal membrane protein characterized as an activation-dependent platelet surface antigen. CD63 antigen has a diverse distribution on the surface and in the cytoplasm of many cell types including lymphoid, myeloid and endothelial cells and melanoma. It is weakly expressed in granulocytes, B and T-cells."}]}]}