Interestingly, postmortem studies of human schizophrenia have shown decreased expression of PV and the 67 KDa isoform of glutamic acid decarboxylase (GAD67), which is an enzyme responsible for GABA synthesis, in PFC of schizophrenia subjects (Akbarian et al., 1995; Volk et al., 2000; Hashimoto et al., 2003; Fung et al., 2010). This evidence concerns the gene GAD1 and schizophrenia.