As described in the future perspectives paragraph Capturing Polyubiquitinated Proteins by Tandem Ubiquitin Binding Entities (TUBEs), TUBEs have to our knowledge not been applied to study Htt ubiquitination while it might yield valuable insight in the polyubiquitin landscape during HD, as the use of another isolated UBA domain, the UBA domain of ubiquilin-2, has been successfully applied to enrich K48-linked polyubiquitinated proteins from HD models and patient samples (Bennett et al., 2007). Here, UBQLN2 is linked to Huntington disease.