MAPT and Alzheimer disease: Knowing that virtually everybody accumulates p-tau in his or her brain, independently of any clinical signs of AD, and taking into account the relationship between cognitive decline and pace of biological aging, the recently published short-term (3.8 year) longitudinal cohort study among 70-year-olds by Villemagne et al. [34] presents a test case for the idea that amyloid accumulation is in itself sufficient and necessary to develop AD and that there is no such thing as primary age-related amyloidosis (PARA) (Fig. 3c).