Many candidate genes in the peripheral blood or postmortem brain from schizophrenia patients have been identified with the differential methylation status associated with schizophrenia [11,85], including nitric oxide synthase 1 (NOS1), AKT serine/threonine kinase 1 (AKT1), DTNBP1, DNMT1, protein phosphatase 3 catalytic subunit gamma (PPP3CC), glutamic acid decarboxylase 67 (GAD67), and sex-determining region Y-box containing gene 10 (SOX10) [86,87]. The gene discussed is GAD1; the disease is schizophrenia.