MAPT and Alzheimer disease: Human evidence has also advanced, including DTI-ALPS studies and a 2026 randomized crossover study reporting higher morning plasma amyloid and tau levels after normal sleep than after sleep deprivation, consistent with greater overnight brain-to-blood clearance during sleep.<h4>Conclusion</h4>Sleep-dependent glymphatic clearance is increasingly recognized as an important component of brain homeostasis and a plausible contributor to AD pathophysiology, with promising implications for biomarker development, prevention, and future therapeutic translation.