Among the most studied proteins in this group are amyloid-β plaques in AD; tau neurofibrillary tangles in frontotemporal dementia with parkinsonism, and AD; α-synuclein Lewy bodies and neurites in PD, and dementia with Lewy bodies; huntingtin inclusions in Huntington’s disease; TDP-43 inclusions in amyotrophic lateral sclerosis; and Prion protein (PrP) inclusions in prion disease (spongiform encephalopathies) [8, 10]. The gene discussed is HTT; the disease is Alzheimer disease.