The distinct involvement of the entorhinal cortex together with the increased tau deposition in the dentate gyrus and CA4 subregion [which is considered to contain pyramidal cells with similar cytoarchitecture and connectivity as those in CA3 but enclosed by the dentate gyrus 27] in a significant subset of sCJD cases indicates a deviation from the distribution seen in typical AD cases. This evidence concerns the gene MAPT and Alzheimer disease.