TNF and Alzheimer disease: The neuroinflammatory response in AD entails a complex response from recruitment of peripheral immune cells including leukocytes and T cells, glial cell activation, induction of intracellular signaling pathways, and release of inflammatory mediators including interleukin-1 (IL-1), interleukin-6 (IL-6), interleukin-18 (IL-18), tumor necrosis factor-α (TNF-α), interferons (IFN) and interleukin-12 (IL-12).