MAPT and Alzheimer disease: In addition, the conversion from MCI to dementia is clearly dependent on the underlying pathology and in particular, the amyloid- and Tau-related pathology, as we specifically track the MCI due to AD that will progress to AD [17]; in the case of cognitive decline measured with the MMSE, it could be aspecific to the underlying pathology and NfL clearly appears as a marker of the neurodegenerative process but is not specific to AD.