MAPT and Alzheimer disease: Several studies indicate that the levels of retromer subunit proteins are reduced in affected brain regions of human tauopathies (Progressive Supranuclear Palsy and Pick’s disease) and Alzheimer’s disease [44, 45], and silencing VPS35 expression in the brain can exacerbate tau neuropathology, and motor and learning impairments in human P301S-tau transgenic mice [45].