Human CD83 is a 40‑50 kDa member of the Siglec (or sialic-acid-binding immunoglobulin-like lectin) family of transmembrane proteins . CD83 is synthesized as a type I transmembrane glycoprotein that contains a 125 amino acid (aa) extracellular region, a 22 aa transmembrane segment, and 39 aa cytoplasmic domain. It contains one V type Ig-like domain in the extracellular region with no inhibitory cytoplasmic motif(s).