Our microarray data reveal that several of these protective mechanisms appear to be engaged in the brain in aging and AD, including upregulation of CFH, CFHR1 and clusterin to curtail complement activation, upregulation of the anti-inflammatory cytokine IL-10, upregulation of CD163, and upregulation of nonclassical MHCI genes (HLA-E and HLA-G). Here, HLA-G is linked to Alzheimer disease.