The tract-specific effect size of the associations between florbetapir-PET SUVR in the fiber tracts and tau-PET SUVR changes in the tract’s projection zones in the AD spectrum group were projected onto the fiber-tract map of MWF to test the hypothesis that late-developing normally lower-myelinated fiber tracts (as assessed in the healthy individuals) are prone to exhibit a stronger effect of myelin alterations on tau deposition in AD. This evidence concerns the gene MAPT and Alzheimer disease.