MAPT and Alzheimer disease: Together, this suggests that WML volume is likely not strongly associated with AD pathology, even though it is associated with cognitive impairment.46 The aetiology of WML is not fully understood, and previous studies have indicated that the aetiology may differ depending on the lobar location of the lesions.47 Examining the influence of regional WML (in interaction with Aβ) on tau accumulation as well as other imaging measures of white matter damage (e.g. diffusion tensor imaging) would be of interest for future research.