Cluster of Differentiation 86 (also known as CD86 and B7-2) is a protein constitutively expressed on dendritic cells, Langerhans cells, macrophages, B-cells (including memory B-cells), and on other antigen-presenting cells. Along with CD80, CD86 provides costimulatory signals necessary for T cell activation and survival. Depending on the ligand bound, CD86 can signal for self-regulation and cell-cell association, or for attenuation of regulation and cell-cell disassociation. When bound to CTLA-4, CD86 can be removed from the surface of an APC and onto the Treg cell in a process called trogocytosis. Blocking this process with anti-CTLA-4 antibodies is useful for a specific type of cancer immunotherapy called "Cancer therapy by inhibition of negative immune regulation".