PSEN1 and Alzheimer disease: Similarly, 5xFAD is another well-established mouse model of AD, where five human genes are genetically modified, including three mutations on amyloid precursor protein (APP) genes, such as mutations in Swedish-(K670N, M671L), Florida- (I716V), as well as and London (V717I) and two mutations on PS1 genes, such as M146L and L286V [17].