BAG3 and Alzheimer disease: These key chaperones include HSPB8, a small heat shock protein that interacts with BAG3, a co-chaperone of HSP70, and that has been shown to facilitate the autophagic removal of a number of aggregation-prone substrates, such as mutated polyglutamine proteins (41,45–47), a mutant SOD1 and a C-terminal truncated fragment of TDP-43 (ΔC-TDP-43) associated with ALS (15,45–47), the β-amyloid peptide associated with AD (48), mutant α-synuclein associated with PD (49), and of other proteins that readily misfold (42,43,50) .