PECAM1 and Alzheimer disease: Mean vascular Aβ levels showed an upward trend in AD patients (Figure 1C), although statistical significance was not reached in CD31+ area (control mean = 9.21, AD mean = 17,82, Z = −1.85847, p = 0.0631) and αSMA+ area (control mean = 9.57, AD mean = 40.55, Z = −1.90476, p = 0.0568).