MAOA and schizophrenia: Although genome-wide studies now implicate hundreds of loci, convergent functional studies keep DISC1, COMT, mono-amine-oxidase-A/B (MAO-A/B), GAD67 (GAD1), and NRG1 as possible triggers for schizophrenia because they link neurodevelopmental liability to the very transmitter and circuit motifs that clozapine ultimately modulates [44].