The initial link with AD was established not only by the identification of Aβ in exosomes but also the presence of exosomal proteins Alg-2 interacting protein (ALIX) and flotillin-1 in Aβ-containing plaques in AD brains (Kokubo et al., 2005; Rajendran et al., 2006). The gene discussed is PDCD6IP; the disease is Alzheimer disease.