DAO and schizophrenia: Genetic studies have revealed a list of astrocyte-related genes associated with schizophrenia, such as D-amino acid oxidase (DAO) [8], excitatory amino acid transporter 2 (EAAT2) [9], excitatory amino acid transporter 4 (EAAT4) [10], S100 calcium-binding protein B (S100β) [11,12,13,14,15], thrombospondin 1 (THBS1) [16], and serine racemase (SR) [17].