We next examined the requirement of UBQLN2 for the clearance of a pathological Huntingtin fragment (HTTQ103), as UBQLN2 has been described to bind to aggregates in mouse models and patients with Huntington’s disease (HD) (Doi et al., 2004, Rutherford et al., 2013). This evidence concerns the gene UBQLN2 and juvenile Huntington disease.