We ruled out other infectious diseases, autoimmune diseases, immunodeficiency, and tumors after obtaining negative results for tests on cytomegalovirus, T. gondii, adenovirus, viral hepatitis, HIV, mycoplasma IgM, TPPA, fungal G and GM, bacterial hemocultures, autoantibodies, humoral and cellular immunity, and tumor markers, as well as negative urine and stool examinations, and chest and abdomen CT images. Here, CD40LG is linked to animal viral hepatitis.