APOE and Alzheimer disease: Interestingly, in AD human tissue samples from the precuneus—a brain region which is involved in learning processes and long-term memory formation independent of the hippocampus—of 162 DAM genes, the authors found 8 genes to be downregulated, whereas the levels of prominent DAM genes (Itgax, Apoe, Csf1, Axl, and Cst7) were not downregulated at all [11].