In this regard, the serological test is one way to detect the origin of infection in its acute or chronic phases of infection.In fact, markedly elevation of serum antibody titers to M. pneumoniae and the detection of specific IgM and IgG antibodies against this microorganism can be one of the serological diagnostic choice to confirm brain stroke specifically caused by Mycoplasma pneumoniae (21). The gene discussed is CD40LG; the disease is infection.