CD8A and Autoimmunity: While CD25+FOXP3+CD4+ Tregs have been regarded as the main player in prevention of autoimmunity, the requirement of CD8+ Tregs cells for maintenance of peripheral tolerance has recently gained interest, where high levels of CD25+FOXP3+CD8+ Tregs cells have been associated with remission of multiple sclerosis29 and reduced graft-versus-host disease response30.