<unk>  is a member of the B7 family, which consists of molecules present at APCs and their receptors present on the T-cells.<unk>  is present specifically on DC, activated B-cells, and macrophages, but also T-cells<unk>  is also a transmembrane glycoprotein and a member of the Ig superfamily. It is composed of 288 amino acids, and its mass is 33 kDa. It consists of two Ig-like extracellular domains (208 AA), a transmembrane helical segment (21 AA), and a short cytoplasmic tail (25 AA). The Ig-like extracellular domains are formed by single V-type and C2-type domains. It is expressed as both monomers or dimers, but predominantly dimmers. These two forms exist in dynamic equilibrium.<unk>  shares 25% of sequences with CD86; however,<unk>  has a ten-fold higher affinity for CD28 and CTLA-4 than CD86. Moreover,<unk>  interacts with its ligand with faster binding kinetics and slower dissociation constants than CD86. Both human<unk>  and CD86 are located at chromosome 3; the exact region is 3q13.3-q21. Human and murine<unk>  share approximately 44% of sequences. Also both human and murine<unk>  are able to cross-react with both human and murine CD28. This indicates that the binding site of<unk>  is conserved.
CD80
CD74
CD86
CD23
CD137
CD22
CD4
CD44