The most studied combined form is known as “common variable immunodeficiency” (CVID), which is a disorder characterized by reduced serum levels of IgG, which can be combined with a reduction of IgA or IgM, or both, which is associated with recurrent sinopulmonary infections, autoimmune disorders, granulomatous diseases, and increased risk of malignancy and altered response of antibodies against infections [6,7]. The gene discussed is CD40LG; the disease is common variable immunodeficiency.