NRG1 and psychiatric disorder: Our finding on novel roles of NRG1-ErbB signaling in sub-ventricular neurogenesis in the developing brain not only would be noteworthy in order to understand a regulatory mechanism for terminal differentiation of neural progenitor cells, that is production of post-mitotic neurons from neural progenitor cells during brain development, but also might be useful for the etiologies of a psychiatric disorder with a defect in sensory-motor gating such as schizophrenia for which NRG1 and ErbB4 are linked as susceptibility loci.