Prefibrillar Htt oligomers isolated from human or mouse HD brain samples may promote amyloid polyglutamine formation; indeed, immunopurification of misfolded Htt, performed on brain homogenates with an antibody capable of recognizing Aβ, α-syn and Htt oligomers, showed the presence of active amyloid seeds [66]. This evidence concerns the gene HTT and Huntington disease.