Deficiency of any one subunit of NADPH oxidase (gp91phox, p22phox, p47phox, p67phox, p40phox; Table 1), or of other factors that contribute to the respiratory burst pathway (CYBC1/Eros, Rac2-GTPase, G6PD, MPO, GSS; Table 2) may culminate in CGD or a CGD-like phagocyte disorder, reviewed in [54]. Here, MPO is linked to chronic granulomatous disease.