IST1 and Alzheimer disease: Feng et al. also found that tau accumulation inhibits autophagosome–lysosome fusion by inhibiting the expression of IST1 (IST1 factor associated with ESCRT-III), which in turn inhibits ESCRT-III (endosomal sorting complex required for transport-III) formation, revealing a vicious circle of tau deposition and autophagy impairment in the chronic progression of AD [38].