PECAM1 and Alzheimer disease: In the Aβ and CD31 colocalization analyses using Spearman rank correlation coefficient, Aβ and CD31 colocalization (H(3) = 12.48, p = 0.0059, mean control = 0.30, mean AD no CAA = 0.30, mean AD mild CAA = 0.32, mean AD severe CAA = 0.40) was higher in patients with severe CAA compared to control patients (Z = 3.40, p = 0.007) and AD patients with mild CAA (Z = 2.49, p = 0.0127) and trending compared to AD patients with no CAA (Z = 1.83, p = 0.068) (Figure 1F).