T-lymphocyte activation antigen CD86 (B7-2) is a glycosylated protein in the B7 family. B7 family members are transmembrane cell surface molecules that play important roles in immune activation and the maintenance of immune tolerance. It is highly expressed on activated antigen presenting cells. CD86 involved in the costimulatory signal essential for T-lymphocyte proliferation and interleukin-2 production, by binding CD28 or CTLA-4. It may play a critical role in the early events of T-cell activation and costimulation of naive T-cells, such as deciding between immunity and anergy that is made by T-cells within 24 hours after activation. It is expressed by activated B-lymphocytes and monocytes and promoted by MARCH8 and results in endocytosis and lysosomal degradation.