ACTA1 and Alzheimer disease: Aβ and αSMA also significantly colocalized more in AD patients with severe CAA (H(3) = 18.24, p = 0.0004, mean control = 0.21, mean AD no CAA = 0.25, mean AD mild CAA = 0.24, mean AD severe CAA = 0.54) compared to control patients (Z = 3.40.