Moreover, the antibody tests revealed negative for tuberculosis antibodies (IgM and IgG), negative for T-SPOT.TB, negative for human immunodeficiency virus, negative for EBV-CA IgG, negative for EBV-CA IgM, and negative for EBV-EA IgA, and that increased serum IgG4 (7.700 g/L, normal 0.020–2.000 g/L). The gene discussed is CD40LG; the disease is tuberculosis.