In Alzheimer’s disease, for example, where extracellular deposition of the β-amyloid (Aβ) peptide, forming the typical neuritic plaque is a major hallmark of the disease, it seems that Aβ represents a DAMP for microglial cells and causes their continuous activation through their toll-like receptors 2, 4, 9 (TLR-2, -4, -9) (33). Here, TLR2 is linked to Alzheimer disease.