Considering that IgM is a T. gondii-specific antibody that appears in the early stage of acute Toxoplasma infection, and as the infection progresses, IgG and IgM antibodies will be observed together, while the IgM will reduce and IgG will keep the high level in the later stage of the infection, and the infection will turn into a chronic T. gondii infection. This evidence concerns the gene CD40LG and infection.