TNF and early-onset autosomal dominant Alzheimer disease: Peripheral hyperinsulinemia, due to insulin resistance and accumulation of Aβ, causes increased cerebral levels of pro-inflammatory cytokines, such as interleukin-1β (IL-1β), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α), which are associated with the inflammatory responses [248], all of which are detected in elevated levels in Alzheimer’s disease [243].