Cell surface glycoprotein CD2 receptor 2, also known as Cell surface glycoprotein CD2 receptor 1-like, Cell surface glycoprotein OX2 receptor 2, CD2 receptor-like 2, CD2Rla, CD2R1L and CD2R2, is a single-pass type I membrane protein which belongs to theCD2R family. CD2R1L / CD2R2. It contains oneIg-like C2-type (immunoglobulin-like) domain and oneIg-like V-type (immunoglobulin-like) domain. CD2 is a transmembrane protein delivering immunoregulatory signals after engagement of CD2R. A family of CD2Rs exist ( CD2R1, CD2R2, CD2R3, CD2R4 ) with different tissue expression and functional activity. In the presence of anti-CD2R2 / CD2R3 monoclonal antibodies (mAbs), bone-marrow cells cultured in the presence of (interleukin [IL]-4+granulocyte-macrophage colony-stimulating factor) differentiate into dendritic cells (DCs), which induce CD4+CD25+ Treg. Interaction between the relatively ubiquitously expressed molecule CD2 and one of its receptors, CD2R1, resulted in direct suppression of alloreactivity, engagement of alternate receptors led instead to altered differentiation of dendritic cells (DCs) from marrow precursors, which could in turn foster development of Foxp3(+) regulatory T cells. Unlike anti-CD2R1, anti-CD2R2 both promotes development of DCs with capacity to induce Treg and directly augments thymocyte production of Treg.