DNAJB1 and Huntington disease: Among the HSP40, HSP70 and HSP110 chaperone families, the DNAJB class of HSP40 emerged as the most potent protector against PolyQ toxicity (Hageman et al., 2010), and, in R6/2 mice, Hsp70 suppressed HD only moderately (Hansson et al., 2003; Hay, 2004; Popiel et al., 2012), while Hsp40 members had better success (Labbadia et al., 2012; Kakkar et al., 2016).