DAO and schizophrenia: The SNPs of DAO previously reported to be associated with schizophrenia are DAO-M4 (rs2111902 at intron 1), DAO-M5 (rs3918346 at intron 3), and DAO-M6 (rs3741775 at intron 4) in Caucasian populations [4–6]; however, this result was not replicated in Chinese [7] and Taiwanese populations [8].