APP and Alzheimer disease: The 5xFAD transgenic (Tg) mouse model expresses human Aβ precursor protein (APP) and presenilin-1 (PSEN1) transgenes with a total of five AD-linked mutations as follows: K670N/M671L (Swedish), I716V (Florida), and V717I (London) mutations in APP, and the M146L and L286V mutations in PSEN1 [17,24].