APP and early-onset autosomal dominant Alzheimer disease: In addition to chronic inflammation and microglia activation in the brain, two key proteins are associated with its development: (1) β-amyloid (βA), which is formed from amyloid precursor protein (APP) and then precipitates and forms plaques between neurons, and (2) tau, which normally maintains normal microtubule structure but in Alzheimer’s disease becomes hyperphosphorylated (TauHF) and aggregates within neuronal bodies.