Among the heat shock proteins (HSPs), known as molecular chaperones, HSP90, HSP70, and HSP32, which are increased in the AD brain, induce the production of IL-6 and TNFα and increase the microglial phagocytosis and clearance of Aβ42 by NF-κB and p38 MAPK activation, via Toll-like receptor 4 (TLR4) [103]. Here, TNF is linked to Alzheimer disease.