CYBB and chronic granulomatous disease: In contrast, CGD patients fail to generate this “respiratory burst” and display enhanced susceptibility to a wide-spectrum of bacterial and fungal infections, with the greatest threat of infection and mortality to X-linked CGD patients (two-thirds of CGD cases, gp91phox-deficient) (Jones et al., 2008; Segal, 2005; Segal et al., 2011; Winkelstein et al., 2000).