From these murine, 5xFAD mice express human APP and PSEN1 transgenes with a total of five AD-linked mutations, namely, APP with K670N/M671L (Swedish mutation28), I716V (Florida mutation29), and V717I (London mutation30), and PSEN1 with M146L and L286V mutations31 to predominantly make Aβ1–42. This evidence concerns the gene PSEN1 and Alzheimer disease.