DNAJB1 and Huntington disease: Hsp40 and Hsp70 colocalise with mutant HTT aggregates (Jana, 2000; Muchowski et al., 2000; Kim et al., 2002; Scior et al., 2018), and their levels reduce with age, coinciding with proteostasis decline and middle-age HD onset (Hay, 2004; Ben-Zvi et al., 2009; Taylor and Dillin, 2011; Brehme et al., 2014; Hipp et al., 2019).