NRG1 and schizophrenia: They include whole-body mutant mouse strains ([48] (Reelin); [49] (Neuregulin-1)), mutant mouse strains in which distinct genes have been knocked down in a tissue- or cell-type-specific manner ([50] (NRG-1/ErbB); [51] (DISC)), and transgenic mice that overexpress schizophrenia-relevant genes ([52] (dopamine D2 receptor); [53] (Neuregulin-1)).