With the advent of the Cryo-EM, which made it possible to analyze at atomic level the filaments of Tau extracted from the brain of AD patients (ex vivo samples), the comparison of their structure with the morphology of filaments, obtained during the in vitro aggregation in cell-free systems, became a practice to better understand if the process might reflect the same result in terms of morphology of the aggregates. This evidence concerns the gene MAPT and Alzheimer disease.