The Cluster of differentiation 80 (also<unk>  and B7-1) is a B7, type I membrane protein in the immunoglobulin superfamily, with an extracellular immunoglobulin constant-like domain and a variable-like domain required for receptor binding. It is closely related to CD86, another B7 protein (B7-2), and often works in tandem. Both<unk>  and CD86 interact with costimulatory receptors CD28 and CTLA-4 (CD152).
CD80
CD74
CD86
CD23
CD137
CD22
CD4
CD44