Opr, or Zic family member 5, is a human gene encoded by ZIC5. It may also be known as: Zinc finger protein ZIC 5; Zinc finger protein of the cerebellum 5. The encoded protein has an amino acid length of 663 and a mass of 68.4 kDa. Other isoforms may exist. Opr is a member of the GLI C2H2-type zinc-finger protein family. Homologs of this gene exist in other organisms, including: Mouse, Rat, Zebrafish, Frog, Chicken.