Our immune system (Immune System) protects us from infections such as bacteria, fungi and viruses in the external environment. Our immune system helps us live a healthy life by fighting infectious agents.  Immunodeficiency occur with recurrent and life-threatening infections as a result of the components of the immune system not working since birth. If severe forms are not treated, death is inevitable in the first year of life. More than 400 immunodeficiency diseases have been reported. Supportive treatments include antibiotics, antifungals, antiviral drugs and IVIG. However, the only definitive treatment is Bone Marrow Transplantation. Experience with gene therapies is increasing.