In the AD brain, it has been shown that microvessels contain elevated levels of interleukin-1β (IL-1β), transforming growth factor-β (TGF-β) and macrophage inflammatory protein-1α (MIP-1α), and they also secrete much higher levels of interleukin-6 (IL-6) than control vessels [325,326]. Here, IL6 is linked to Alzheimer disease.