V-set and immunoglobulin domain-containing protein 8(VSIG8) is a single-pass type I membrane protein.The human VSIG8 cDNA encodes 414 amino acids (aa) including a 21 aa signal sequence, a 242 aa extracellular domain (ECD) containing 2 Ig-like V-type (immunoglobulin-like) domains, a 21 aa transmembrane domain and a 130 aa cytoplasmic domain.The funtion of VSIG8 is not clear.