Interest has grown in the role of DAO in several neuropsychiatric disorders, especially schizophrenia, a disorder in which NMDA receptor-related hypofunction is pathophysiologically implicated (Javitt and Zukin, 1991; Olney et al., 1999; Tsai and Coyle, 2002; Kantrowitz and Javitt, 2010; Marek et al., 2010; Coyle, 2012) and is a target of much therapeutic research (Krystal et al., 2010; Moghaddam and Javitt, 2012). The gene discussed is DAO; the disease is schizophrenia.