In addition, the filaments derived from alpha‐synuclein, polyQ‐expanded huntingtin, and beta‐amyloid, which are associated with the neurodegenerative disorders such as Parkinson's, Huntington‘s, and Alzheimer's diseases, respectively, also trigger ER stress in neurons (Smith et al, 2005; Kim et al, 2008; Leitman et al, 2013). The gene discussed is HTT; the disease is early-onset autosomal dominant Alzheimer disease.