A systematic inflammation apparently seems to play a significant role in the onset and progression of AD.11,16,34 Elevated systemic levels of inflammatory mediators, i.e. interleukin (IL)-1β, IL-6 und tumor necrosis factor α (TNF-α), have been demonstrated to be associated with the neuronal degeneration found in AD.3,26 Many studies indicate that an infection triggering an inflammatory response may be linked to AD.18,20,39. The gene discussed is TNF; the disease is infection.