AXCAM, or Contactin 4, is a human gene encoded by CNTN4. It may also be known as: Contactin-4; Brain-derived immunoglobulin superfamily protein 2; BIG-2. The encoded protein has an amino acid length of 1026 and a mass of 113.5 kDa. Other isoforms may exist. AXCAM is a member of the Immunoglobulin superfamily, Contactin family. Homologs of this gene exist in other organisms, including: Mouse, Rat, Zebrafish, Frog, Chicken.