In ‘The Sleeping Brain’ article, the authors suggest that sleep disturbance causes reduced removal of the waste products from the brain, leading to the accumulation of beta amyloids - which in turn is observed in Alzheimer's disease. Studies present an association between APOE4 and sleep disturbance. Additionally APOE4 is linked to sleep disturbance before the onset of Alzheimer's symptoms. Additionally, it is thought that APOE directly leads to beta amyloid metabolism disturbance. And, finally, it is thought that stress-related proteolytic cleavage of APOE4 leads to accumulation of tau proteins. Let's review the evidence.