This gene encodes a cell surface glycoprotein that regulates complement-mediated cell lysis，and it is involved in lymphocyte signal transduction. This protein is a potent inhibitor of the complement membrane attack complex，whereby it binds complement C8 and/or C9 during the assembly of this complex，thereby inhibiting the incorporation of multiple copies of C9 into the complex，which is necessary for osmolytic pore formation. This protein also plays a role in signal transduction pathways in the activation of T cells. Mutations in this gene cause CD59 deficiency，a disease resulting in hemolytic anemia and thrombosis，and which causes cerebral infarction. Multiple alternatively spliced transcript variants，which encode the same protein，have been identified for this gene. [provided by RefSeq，Jul 2008]