TNF and Alzheimer disease: Infectious factors are responsible for the activation of glial cells that produce several inflammatory molecules, including cytokines such as tumor necrosis factor (TNF)-α, interferon-γ (IFN-γ), interleukin (IL)-6, IL-1β, IL-18, chemokines, and reactive oxygen species (ROS) which in turn leads to exacerbation of other AD pathologies.