NRGN and Alzheimer disease: A cluster of CSF biomarkers, namely Tau, neurogranin, SNAP25 in this study, and also alpha-synuclein, Visinin-like protein-1 (VILIP-1), GAP43 and Beta-secretase 1 (BACE-1) levels are increased in MCI and AD and correlate highly with one another [6,9,36,37].