In addition to Ng, other synaptic proteins, such as synaptotagmin-1 (SYT-1), synaptosomal-associated protein-25 (SNAP-25) and growth-associated protein-43 (GAP-43), have been detected in CSF of AD patients and are a promising group of biomarkers, highlighting the importance of synaptic dysregulation in the disease [92–94]. Here, GAP43 is linked to Alzheimer disease.