This paper talks about the well known link between the APOE4 gene and Alzheimer's disease. There is also a well known link between APOE4 and heart disease. I think that Alzheimer's and heart disease are caused by Chlamydophila pneumoniae (CPN). There is some evidence that people with the APOE4 gene are more susceptible to CPN infections. This article suggests to me that Alzheimer's, like heart disease, begins with childhood CPN infections. Russ www.potbellysyndrome.com