As a biomarker of synaptic dysfunction, previous studies reported that the concentration of CSF GAP-43 was elevated in AD patients5,18–20, and in this present study we analyzed whether CSF GAP-43 is associated with other CSF and blood biomarkers in AD and whether the baseline levels of CSF GAP-43 could predict changes in cognitive measurements and neuroimaging findings over time. The gene discussed is GAP43; the disease is Alzheimer disease.