DLG4 and schizophrenia: PSD-95 (6 studies, ES = −0.34, p = 0.14), VAMP (6 studies, ES = −0.26, p = 0.27), and syntaxin (6 studies, ES = 0.16, p = 0.52) protein levels did not differ in frontal cortex between schizophrenia patients and controls (Supplementary Figures 4–6).