Hahn et al. reported that NRG1-induced ErB4 activation is significantly reduced in the brains of mice treated with haloperidol compared with controls treated with vehicle alone, and that enhanced NRG1 signaling may contribute to N-methyl-D-aspartate (NMDA) receptor hypofunction in schizophrenia [27]. Here, NRG1 is linked to schizophrenia.