CD40LG and early-onset autosomal dominant Alzheimer disease: Viral DNA is found in amyloid plaques [14], which are also heavily enriched in proteins used by the virus during its life cycle, as well as in proteins related to the immune network [15], and Immunoglobulin IgM, but not IgG seropositivity for herpes simplex is predictive of the subsequent development of Alzheimer's disease [16].