G-protein coupled receptor 139 (GPC139) is a protein that in humans is encoded by the GPR139gene.[5][6] Research has shown that mice with loss of GCP139 experience schizophrenia-like symptomatology that is rescued with the dopamine receptor antagonist haloperidol and the μ-opioid receptor antagonist naltrexone.[7][8]
^Vedel L, Nøhr AC, Gloriam DE, Bräuner-Osborne H. Pharmacology and function of the orphan GPR139 G protein-coupled receptor. Basic Clin Pharmacol Toxicol. 2020 Jun;126 Suppl 6(Suppl 6):35-46. doi:10.1111/bcpt.13263PMID31132229