It is worth noting that the current results are largely inconsistent with the notion that the lowest quartile can be explained simply by AD severity marked by tau burden based on at least three findings: (1) cognitive and structural imaging differences persisted after controlling for tau, (2) additional analyses estimating time to tau positivity – an approach that aligns individuals by biological stage – showed domain‐specific differences even prior to tau onset, and (3) autopsy validation confirmed enrichment for TDP‐43 pathology. This evidence concerns the gene MAPT and Alzheimer disease.