In contrast to the IgG autoantibody, the frequency of anti-ATCAY IgM autoantibody did not differ among patients with AD or MCI and NC groups, suggesting the the anti-ATCAY autoantibody detected in patients may be resulted from a chronic exposure of ATCAY autoantigen to the immune system rather than a short-term or acute exposure24,25. This evidence concerns the gene CD40LG and Alzheimer disease.