It seems that the level of Aβ correlated to onset of AD, as indicated by familial AD (FAD) patients, including those carrying mutations on the amyloid precursor protein (APP) [2], a disintegrin and metalloproteinase 10 (ADAM10, an α-secretase) [3,4] and/or presenilin-1/2 (PS1/2, the components of γ-secretase) [5] which give rise to the overproduction of Aβ, probably suffer from AD during their younger life. Here, PSEN1 is linked to familial Alzheimer disease.