IL17A and early-onset autosomal dominant Alzheimer disease: The role of IL-17 in the pathogenesis of Alzheimer's disease has been assessed using the triple-transgenic Alzheimer's disease and intracerebroventricular (i.c.v.)injection of Aβ1-42 models.14,35 IL-17+ cells were shown to accumulate in the brain at the onset of neurodegenerative symptoms.