ACE2 and Alzheimer disease: We quantified ACE2 protein levels in both 3xTg-AD and non-transgenic mice from two different cohorts: (i) mice of 4 or 6, 12, and 18 months of age, (ii) and 18-month-old mice fed either a control or a HFD that exacerbates neuropathology [83] (Fig. 6).