Trace amine-associated receptor 2 (TAAR2), formerly known as G protein-coupled receptor 58 (GPR58), is a protein that in humans is encoded by the TAAR2 gene. TAAR2 is coexpressed with G? proteins; however, as of February 2017, its signal transduction mechanisms have not been determined. Human TAAR2 (hTAAR2) is expressed in the cerebellum, olfactory sensory neurons in the olfactory epithelium, and leukocytes (i.e., white blood cells), among other tissues.[7][8] hTAAR1 and hTAAR2 are both required for white blood cell activation by trace amines in granulocytes.[9] Phenethylamine, para-tyramine, and 3-iodothyronamine are full agonists of hTAAR2 with EC50 values of 0.43 ± 0.05 nM, 0.52 ± 0.05 nM, and 0.25 ± 0.04 nM respectively. A single nucleotide polymorphism nonsense mutation of the TAAR2 gene is associated with schizophrenia. TAAR2 is a probable pseudogene in 10–15% of Asians as a result of a polymorphism that produces a premature stop codon at amino acid 168.