In DS and AD brains dense fibrillary p-Tau present in “psammoma bodies” (calcified intracellular inclusion structures), was visible in the stroma, whereas in DS brains ApoE was visible in the “amyloid biondi” bodies (complex filamentous ring-like structures associated with lipid droplets) and lipofuscin (yellow or brown intracellular structures composed of lipid molecules). This evidence concerns the gene APOE and Alzheimer disease.