ATXN3 and cerebellar degeneration: Several mouse models of SCA3 have been developed over the years, using both transgenic and knock-in approaches, and many of these models recapitulate the ataxia-like behavior, inclusion pathology, and cerebellar degeneration expected of SCA3 (Ikeda et al., 1996; Cemal et al., 2002; Goti et al., 2004; Bichelmeier et al., 2007; Chou et al., 2008; Torashima et al., 2008; Boy et al., 2009; Boy et al., 2010; Silva-Fernandes et al., 2010; Simoes et al., 2012; Nobrega et al., 2013a; Silva-Fernandes et al., 2014; Ramani et al., 2015; Switonski et al., 2015; Haas et al., 2021).