In addition, [18F]PI-2620 PET signals in tau vulnerable regions in AD patients are generally higher than in patients with 4R tauopathies which can be attributed to a stronger binding of [18F]PI-2620 to AD-type 3/4R tau and a faster clearance for [18F]PI-2620 tracer in 4R tauopathies [23]. Here, MAPT is linked to Alzheimer disease.