STAT3 and Alzheimer disease: Specifically, we found that 1) Aβ species applied to cultured vascular cells increase activated forms of STAT3 and produce oxidative stress in a STAT3-dependent manner; 2) CAA-laden cerebral vessels from aged 5XE4 mice and autopsied AD patients have markedly increased levels of activated STAT3; and 3) pharmacologic inhibition of STAT3 reduces CAA load, improves cerebral hemodynamics, and restores functional network communication in aged 5XE4 mice.