In sum, our study thus provides a translational line of evidence showing that alterations in E/I balance and pre‐attentive stimulus processing, which are considered biomarkers/endophenotypes of psychiatric disorders (Coyle, 2006; Javitt et al, 2008, 2011) and are present in PRG‐1+/mut carriers, result from a reduced PRG‐1 action at the synapse, leading to increased LPA levels and loss of proper cortical network function. Here, PLPPR4 is linked to psychiatric disorder.