Molecular mechanistic investigations revealed that endosomal sorting complex required for transport (ESCRT) III subunit charged multivesicular body protein 4B (CHMP4B), which is essential for autophagosome-lysosome fusion, was significantly decreased in the cerebral cortex of AD patients and the hippocampus of MAPT P301L mice. The gene discussed is CHMP4B; the disease is Alzheimer disease.