NADPH oxidase-dependent production of superoxide is involved in the increase in oxidative stress that is observed in a variety of brain disorders, including cerebral ischemia (Sugawara and Chan, 2003; Suh et al., 2008; Yoshioka et al., 2011), traumatic brain injury (Dohi et al., 2010), sepsis-associated encephalopathy (Hernandes et al., 2014), and psychiatric disorders as well as Alzheimer’s disease, Parkinson’s disease and other neurodegenerative diseases (Sorce and Krause, 2009). Here, FMO5 is linked to early-onset autosomal dominant Alzheimer disease.