The present invention provides a protein encoded by the ATP2B gene and discloses the differential expression of the gene coding for ATP2B proteins in specific brain regions of Alzheimer's disease patients. Based on this finding, the invention provides a method for diagnosing or prognosticating Alzheimer's disease in a subject, or for determining whether a subject is at increased risk of developing Alzheimer's disease. Furthermore, this invention provides therapeutic and prophylactic methods for treating or preventing Alzheimer's disease and related neurodegenerative disorders using the ATP2B gene and its corresponding gene products. A method of screening for modulating agents of neurodegenerative diseases is also disclosed.