Nevertheless, VCA-IgM might appear later, or might be produced only transiently, or might persist at such a low concentration as to be missed by laboratory tests and the low and high affinity IgG have different significance during EBV infection, low affinity anti-VCA IgG suggests a early stage infection and high anti-VCA IgG suggests post infection[6]. The gene discussed is CD40LG; the disease is Epstein-Barr virus infection.