APOE4 genotype is associated with increased Alzheimer's risk.

“apo e is made in the brain it's made by cell types like microglia in the brain and it's a lipid binding protein that you know transports lipids and now we know from genetics of Alzheimer's that there are lots of other lipid genes that are related to Alzheimer's so the story starts with the fact that apoe made in the brain is somehow impacting on Alzheimer's risk and if you have this form of apoe4 and especially if you have two forms of apoe4 you were at very substantially increased risk of Alzheimer's for reasons that we still don't fully understand but as a lipidologist I think it has something to do with lipid transport in the brain”