The majority of the findings suggest that the level of expression of GRM3 mRNA is unaffected in schizophrenia (Ohnuma et al., 1998; Richardson-Burns et al., 2000; Egan et al., 2004; Bullock et al., 2008; Ghose et al., 2008; Gonzalez-Maeso et al., 2008). This evidence concerns the gene GRM3 and schizophrenia.