In bilateral salience/executive-related regions implicated in bvFTD, we found a lower ratio of layer pathology in bvFTD-tau compared to bvFTD-TDP (β = − 0.63, SE = 0.12, p < 0.001) (Fig. 8a); all other effects were non-significant (p > 0.2). Here, MAPT is linked to behavioral variant of frontotemporal dementia.