Overexpression of mutant Httex1 alone with polyQ length ranging from 80 to 175 reproduces many aspects of HD pathology in various animal and cellular models, including the formation of huntingtin inclusions (Mangiarini et al., 1996; Martindale et al., 1998; Scherzinger et al., 1999; Barbaro et al., 2015). The gene discussed is HTT; the disease is Huntington disease.