Analysis of schizophrenia ‘at risk' polymorphisms associated with changes in NRG1 and ErbB4 mRNA levels, as well as a de novo microdeletion of ERBB4, suggest altered NRG/ErbB4 signalling can result in behavioural impairments resembling aspects of schizophrenia44, 49. Here, ERBB4 is linked to schizophrenia.