This gene contains a genome-wide significant locus identified by the latest schizophrenia GWAS4 and is involved in several critical biological processes during early brain development, such as neuron differentiation and neural stem cell proliferation.98,99 Thus, given the strong evidence for the involvement of the EMX1 gene in schizophrenia and in P300 amplitude deficits, further research should seek to characterize its functions using cellular and animal models as well as other endophenotypes in humans. The gene discussed is EMX1; the disease is schizophrenia.