Although regional vulnerabilities to the expression of MAPT are not well understood, PD H1 homozygotes show greater frontal and temporal-parietal atrophy (Sampedro et al., 2018) and decreased posterior cortex activation relative to PD H2 carriers (Nombela et al., 2014; Winder-Rhodes et al., 2015). Here, MAPT is linked to Parkinson disease.