Drawing from the knowledge obtained in the initial IP–MS studies, antineurogranin antibodies directed at the C-terminal part of neurogranin have been used to develop immunoassays (77, 83, 84), and the initial findings have been verified in several studies (85) with neurogranin consistently showing increased levels in CSF of AD patients as compared with controls. This evidence concerns the gene NRGN and Alzheimer disease.