According to the mode of inheritance, two classical forms of the CGD are known: an autosomal form, with mutations in genes encoding for p22phox (CYBA), p47phox (NCF1), p67phox (NCF2), and p40phox (NCF4) proteins and the X-linked form of CGD with mutations present in CYBB encoding NOX2, which accounts for more than 60% of all CGD cases. The gene discussed is NCF2; the disease is chronic granulomatous disease.