GAD2 and schizophrenia: The shared genes reflect remarkably on the nature and most consistently observed features of schizophrenia: 6 shared genes are glutamate receptors (GRIA4, GRIK3, GRIK5, GRIN1, GRM1, GRM2), one GABA receptor (GABBR1), a cannabinoid receptor (CNR1), GAD2, a glutamate decarboxylase, two synapse-related (SYN2, SYT11) and several neuron-specific genes are also present among the shared genes (Fig. 3c).