PECAM1 and Alzheimer disease: In analyzing the CHID1 expression level in the brains of 500 AD males, we have been able to ascertain that its expression levels were correlated with IBA1 (r = 0.1781, p < 0.0001), CALB1 (r = 0.095, p =0.036), and NRGN (r = 0.1791, p < 0.00001) but not to CD31 (r = 0.081, p = ns) (Figure 5B).