Plays an indispensable role in the organization of KRT8/KRT18 filaments. Acts as an endogenous molecular chaperone for neuronal proteins including huntingtin. Has a stimulatory effect on the ATPase activity of HSP70 in a dose-dependent and time-dependent manner and hence acts as a co-chaperone of HSP70. Reduces huntingtin aggregation associated with HD. Also reduces cellular toxicity and caspase-3 activity. This evidence concerns the gene KRT18 and Huntington disease.