Three out of four studies examining mGluR5 protein in post-mortem brain samples from schizophrenia subjects (number of subjects ranging from 9 to 37) identified no change in mGluR5 protein (monomer) levels in the prefrontal cortex (PFC), specifically Brodmann’s areas (BA) 9, 10, 11, 32 and 46 as well as the caudate, putamen and nucleus accumbens [17-19]. This evidence concerns the gene GRM5 and schizophrenia.