Our results showed that PSD95 protein levels were significantly reduced in schizophrenia subjects compared with controls, after co-varying for brain pH and post mortem interval (−61.84%; F1,34=24.985, P<0.001; Figure 1a); these were variables associated with PSD95 protein levels (brain pH: r=−0.331, P=0.042 in all subjects and r=−0.542, P=0.017 in controls; post mortem interval: r=0.544, P=0.016 in schizophrenia subjects; Supplementary Table 1). The gene discussed is DLG4; the disease is schizophrenia.