NRGN and Parkinson disease: In cerebrospinal fluid (CSF) studies of patients with MSA, Parkinson’s disease (PD), progressive supranuclear palsy (PSP), corticobasal syndrome (CBS), dementia with Lewy bodies (DLB) and Alzheimer’s disease (AD), different levels of neurogranin were detected, which were reduced in MSA, PD and PSP and increased in AD compared to controls [21,46].