Due to the inclusion in the present study of phenotypes that typically have an underlying FTLD pathology, either with tau proteinopathy (FTLD-tau) or TDP-43 (FTLD-TDP), this finding signifies the importance of the Aβ42/Aβ40 ratio in differentiating between AD pathology and FTLD. This evidence concerns the gene TARDBP and Alzheimer disease.