In contrast, individuals with chronic granulomatous disease (CGD), a genetic disease with impaired NADPH oxidase activity, as well as mice that lack components of the NADPH oxidase are strongly susceptible to microbial infection (Hampton et al., 1998; Holmes et al., 1967; Mandell, 1974; Segal, 2005; Segal et al., 2000; Vethanayagam et al., 2011; Winkelstein et al., 2000). Here, FMO5 is linked to chronic granulomatous disease.