She did not have tonsils or palpable lymph nodes. T cell lymphocyte as well as neutrophil workups were normal (Table 1). Due to complete absence of B lymphocytes, low levels of IgG and undetectable levels of IgA and IgM, treatment with monthly intravenous immunoglobulin (IVIg) infusion was initiated, achieving normal IgG levels and exhibiting marked improvement of infections, as well as a substantial decrease in gastrointestinal symptoms. This evidence concerns the gene CD40LG and infection.