GPR57, or Trace amine associated receptor 3 (gene/pseudogene), is a human gene encoded by TAAR3. It may also be known as: Putative trace amine-associated receptor 3; hTaar3; G-protein coupled receptor 57; Trace amine receptor 3; TAAR2. The encoded protein has an amino acid length of 343 and a mass of 39.1 kDa. Other isoforms may exist. GPR57 is a member of the G-protein coupled receptor 1 family. Homologs of this gene exist in other organisms, including: Mouse, Rat, Frog.