Ultrastructural analysis of the brain vasculature in 5XFAD mice [which express mutant human APP with the Swedish mutation, Florida mutation (I716V), and London mutation (V717I), as well as human presenilin-1 harboring two familial AD mutations (M146L and L286V)] showed TJs that were significantly shorter (Kook et al., 2012). This evidence concerns the gene PSEN1 and Alzheimer disease.