Cluster of Differentiation 86 (CD86) also known as B-lymphocyte activation antigen B7-2, is a type I membrane protein that is a member of the immunoglobulin superfamily. It is constitutively expressed on interdigitating dendritic cells, Langerhans cells, peripheral blood dendritic cells, memory B cells, and germinal center B cells. Additionally, B7-2 is expressed at low levels on monocytes and can be upregulated through interferon γ. CD86 is the ligand for two proteins on the T cell surface: CD28 (for autoregulation and intercellular association) and CTLA-4 (for attenuation of regulation and cellular disassociation). CD86 and CD80 together prime T cells. B7-2 was shown to promote the generation of mature APC (antigen presenting cells)