Some of the largest Ab studies to date (with > 1000 schizophrenia patients), which were limited to blood serum examinations, have shown similar prevalence rates of different Abs (across all Ab classes, especially IgA and IgM isotypes) in the serum of patients with schizophrenia and controls, predominantly with very low Ab titers [13, 33]. The gene discussed is CD40LG; the disease is schizophrenia.