MAPT and Alzheimer disease: Longitudinal tau-PET data was available for 78 individuals with PCA-AD or lvPPA-AD (PCA-AD n = 45, mean follow-up time: 1.40 ± 0.63 years, range: 0.77–3.16 years; lvPPA-AD n = 33, mean follow-up time: 1.41 ± 0.78 years, range: 0.79–4.07 years).