Our observed reduction in striatal and cortical mr-gef expression in Dlx1/2 −/− mice, together with the previously reported observation that Dlx1 expression is decreased in the mediodorsal thalamic nucleus (MDTN) in patients with psychosis [30], prompted us to determine whether MR-GEF expression was perturbed in individuals with psychiatric disorders. The gene discussed is DLX1; the disease is psychiatric disorder.