It has been suggested that multiple brain waste efflux systems, including the glymphatic system and intramural peri-arterial drainage pathway (IPAD), are possibly impaired in AD,47,48 If the EV efflux pathway currently unidentified is impaired during AD progression, EV CatB efflux into blood will be reduced as the pathology progresses. The gene discussed is TYRP1; the disease is Alzheimer disease.