These include amyloid-β (Aβ) peptides in Alzheimer’s disease (AD); tau in multiple tauopathies (including AD); α-synuclein (αS) in Parkinson’s disease (PD); huntingtin (HTT) in Huntington’s disease (HD); and TAR DNA-binding protein-43 (TDP-43) and fused in sarcoma (FUS) protein in amyotrophic lateral sclerosis and frontotemporal lobar degeneration (FTLD; reviewed in Uversky, 2014, 2015). The gene discussed is MAPT; the disease is juvenile Huntington disease.