(cluster of differentiation)
Any group of antigens that is associated with a specific subpopulation of human T cells. The differentiation antigens expressed by a T cell vary with its stage of development and thus with its role in the immune response. Hence, for example, CD4 antigens are expressed by helper T cells, whereas CD8 antigens are expressed by cytotoxic T cells. The antigens are glycoproteins and are characterized using monoclonal antibodies.
Subjects: Biological Sciences.