Further co-expression analysis in large brain tissue expression datasets and mouse single neurons demonstrated a significant correlation between the expression of CHRM3 or its mouse homologous Chrm3, and that of three genes (GABRG2, CHRNA4, and HRH3) that have been shown to affect risk for psychotic disorders, including schizophrenia. The gene discussed is GABRG2; the disease is schizophrenia.