NRGN and Alzheimer disease: Similarly, several CSF markers of cerebrovascular integrity, such as soluble platelet-derived growth factor receptor β (PDGFRB), intercellular adhesion molecule 1 (ICAM1), vascular cell adhesion molecule 1 (VCAM1), and vascular endothelial growth factor (VEGFs), synaptic markers including neuronal pentraxin-1 (NPTX1) and neurogranin (NRGN), have been associated with AD and cognitive decline [18, 21–28].