DAOA (D-amino acid oxidase activator) is a candidate schizophrenia susceptibility gene located on chromosome 13 that regulates D-serine metabolism through modulation of D-amino acid oxidase (DAO). The gene's molecular function remains controversial: while initially characterized as a DAO activator 12, subsequent studies demonstrate that DAOA may suppress DAO activity and promote protein degradation 345. Cell-type-dependent effects suggest DAOA increases DAO activity in kidney cells but shows no effect in neuronal or astrocyte cells 6. DAOA also promotes degradation of D-aspartate oxidase (DDO) and may participate in mitochondrial fission 78. Mechanistically, DAOA regulates N-methyl-D-aspartate (NMDA) receptor function indirectly by controlling D-serine levels 9. Genetically, DAOA polymorphisms show inconsistent associations with schizophrenia across populations: certain variants (rs778293, rs3916971) associate with schizophrenia primarily in Asian cohorts 10, while meta-analyses suggest weak or non-significant associations overall 11. DAOA expression is tightly regulated, brain region-specific, and age-dependent 12. Understanding DAOA's cell-type-specific mechanisms remains essential for clarifying its role in psychiatric disease pathogenesis 13.