MAPT and Alzheimer disease: Moreover, the relationship between Aβ- and tau-PET differed between individuals with and without a history of TBI, where subjects with a history of TBI had stronger Aβ-related tau accumulation in regions that typically accumulate tau late in Alzheimer’s disease, while the relationship between Aβ and tau was weaker in temporo-parietal brain regions that accumulate tau early in Alzheimer’s disease.