Dr. Lan's latest paper was published in Annals of Neurology. This paper explored how CSF GAP43 relates to Aβ and tau pathologies, neurodegeneration biomarkers, and cognitive decline in elderly adults. We found CSF GAP43 was specially increased in individuals with tau pathology regardless of Aβ plaques and was negatively associated with faster hippocampal atrophy, hypometabolism, and cognitive decline. Our findings suggested that the tau-related presynaptic dysfunction measured by CSF GAP43 may be helpful as an additional biomarker beyond current measurements of neurodegeneration providing more information to understand the characteristics and progression of AD.