PSEN1 and Alzheimer disease: On the other hand, 5xFAD mice overexpress the human APP695 isoform and the human PS1 with a total of five AD-linked mutations, as follows: the Swedish (K670N/M671L), Florida (I716V), and London (V717I) mutations in APP, and the M146L and L286V mutations in PS1, under the control of the murine Thy-1-promoter [33].