Neuregulin-1 (NRG1) is a gene that has been associated with increased risk for schizophrenia across diverse populations.1–3 Studies on postmortem brain and serum from schizophrenia cases have reported up-regulation of specific NRG1/ErbB4 splice variants and increased NRG1 signaling,4–9 and decreased isoform-specific expression of NRG1 transcripts.9,10 However, despite such combined genetic and pathologic evidence for NRG1 dysregulation in schizophrenia, the mechanisms underlying this association remain unclear.11 Here, ERBB4 is linked to schizophrenia.