CD2

CD2 (cluster of differentiation 2) is a is_associated_with::cell adhesion molecule found on the surface of is_associated_with::T cells and natural killer (NK) cells. It has also been called T-cell surface antigen T11/Leu-5, LFA-2, LFA-3 receptor, erythrocyte receptor and rosette receptor.

Function
It interacts with other adhesion molecules, such as lymphocyte function-associated antigen-3 (LFA-3/is_associated_with::CD58) in humans, or is_associated_with::CD48 in rodents, which are expressed on the surfaces of other cells.

In addition to its adhesive properties, CD2 also acts as a is_associated_with::co-stimulatory molecule on T and NK cells.

Diagnostic relevance
CD2 is a specific marker for T cells and NK cells, and can therefore be used in is_associated_with::immunohistochemistry to identify the presence of such cells in tissue sections. The great majority of T cell is_associated_with::lymphomas and is_associated_with::leukaemias also express CD2, making it possible to use the presence of the antigen to distinguish these conditions from B cell is_associated_with::neoplasms.

Classification
Due to its structural characteristics, CD2 is a member of the is_associated_with::immunoglobulin superfamily; it possesses two immunoglobulin-like domains in its is_associated_with::extracellular portion.

Interactions
CD2 has been shown to interact with is_associated_with::CD2BP2, is_associated_with::Lck and is_associated_with::PSTPIP1.