DLG4 and schizophrenia: PSD-enriched fractions from people with schizophrenia had 20% less NR1 protein (t(66)=−2.874, P=0.006; Figures 3a and c) and 30% less PSD-95 protein (t(63)=−2.668, P=0.010; Figures 3b and d) than PSD-enriched fractions from controls.