CRIg, or V-set and immunoglobulin domain containing 4, is a human gene encoded by VSIG4. It may also be known as: V-set and immunoglobulin domain-containing protein 4; Protein Z39Ig; Z39IG. The encoded protein has an amino acid length of 399 and a mass of 44.0 kDa. Other isoforms may exist. Homologs of this gene exist in other organisms, including: Mouse, Rat, Frog, Chicken.