KDR and Alzheimer disease: Independent of changes in VEGF-A levels, the microvascular perturbation is suggested to occur in AD by direct Aβ-VEGFR-2 interaction, that counteracts VEGF-A-induced receptor activation [78], or by VEGF-A segregation in Aβ fibrillar aggregates [79], a process that starts at the beginning of the pathology and enhances when AD progress [80].