Since elevated levels of IgM antibodies to T. gondii following reactivation or re-infection have been reported, Dickerson et al. [61] hypothesized that individuals with elevated IgM had undergone infection with or reaction to T. gondii around the time of their hospitalization for a manic episode, according to the fact the IgM antibody levels decreased over time. The gene discussed is CD40LG; the disease is infection.