X-linked Chronic Granulomatous Disease (CGD) is an inherited disorder caused by an abnormal gene that fails to make the protein known as gp91 phox. This protein is part of a group of proteins that work to create hydrogen peroxide in neutrophils. Neutrophils are a type of white blood cell that helps fight infections. As a result, patients who do not make this gp91 phox frequently develop life-threatening infections. In addition, these neutrophils often act abnormally, resulting in the creation of a granuloma, which is an abnormal collection of cells. These granulomas can then become large enough to block organs, such as the bladder and/or intestines, causing significant problems. Patients are usually treated with antibiotics (often needed for extended periods of time) for the infections caused by CGD, and with corticosteroids for the granulomas. However, these drugs do not cure CGD itself, and can have significant side effects. Thus patients with CGD do not have a normal life expectancy.