GNAO1 and schizophrenia: In the largest microarray study of lymphoblastoid cells so far by Vawter et al. (2004) it was found that the expression of neuropeptide Y (NPY) and the gene that encodes for Guanine nucleotide-binding protein G(o) subunit alpha (GNA01) were reduced in schizophrenia and there was an increase in the mitochondrial-related gene malate dehydrogenase 1, NAD (MDH1) (Vawter et al., 2004).