MARVELD2 and juvenile Huntington disease: Since mhtt oligomers and fibrillar aggregates are strongly implicated in the pathogenesis of Huntington’s disease (Sathasivam et al., 2010), the interactions that we describe between TRiC and mhttQ51 provide a structural mechanism for the chaperonin’s aggressive inhibition of mhtt aggregation in vitro and suggest a potential for TRiC-inspired therapeutics (Sontag et al., 2013).