GRM3 and schizophrenia: A genome-wide association study (GWAS) revealed notable associations relevant to the major hypotheses of the etiology and treatment of schizophrenia, including DRD2 (the main target of many effective antipsychotics) and multiple genes [e.g., metabotropic glutamate receptor 3 (GRM3), glutamate ionotropic receptor NMDA type subunit 2A (GRIN2A), serine racemase (SR), and glutamate receptor, ionotropic, AMPA receptor 1 (GRIA1)] involved in glutamatergic neurotransmission and synaptic plasticity (13).