DAOA encodes D-amino acid oxidase activator, a protein involved in regulating D-serine metabolism in the brain. The functional relationship between DAOA and its target D-amino acid oxidase (DAO) remains controversial: while some evidence suggests DAOA activates DAO to oxidize D-serine, a co-agonist of N-methyl-D-aspartate receptors, recent studies demonstrate cell-type-dependent effects, with DAOA increasing DAO activity in kidney cells but having no effect in neuronal and astrocyte models 1. DAOA expression is tightly regulated and shows both age- and brain region-dependent patterns, with DAOA protein detectable across multiple brain regions despite limited mRNA expression 2. Genetically, DAOA variants have been associated with schizophrenia susceptibility, particularly in Asian populations (rs778293, rs3916971) 3, and specific polymorphisms show associations with bipolar disorder and potentially citalopram treatment response in major depression 4, 5. However, meta-analyses of common polymorphisms (M15, M18, M23) have yielded inconsistent results across psychiatric disorders 6. These genetic associations implicate DAOA in glutamatergic neurotransmission dysfunction hypothesized in schizophrenia and other neuropsychiatric conditions, though the precise molecular mechanisms remain to be fully elucidated.