Expression of GRIK2 is reduced inpeople with schizophrenia19.Metabotropic receptors are also promising candidates for modifiers of the disorder.Schizophrenia patients have been found to have decreased methylation of theglutamate receptor, metabotropic 2 and 5 (GRM2 and GRM5)20. This evidence concerns the gene GRM2 and schizophrenia.