GRN and Alzheimer disease: These findings indicate that alterations in Aβ42 and progranulin levels are not restricted to AD and FTD-GRN subjects, respectively, but are a recurrent finding in other FTD subjects, representing possible downstream effects of mutations in other FTD genes (here: GRN/CHCHD10) and/or concomitant age-related amyloid/progranulin pathology.