NEFL and frontotemporal dementia: Similarly, in the FTD spectrum, higher basal CSF and/or blood NfL values have been related to faster disease progression (in some clinical syndromes) (Ljubenkov et al., 2018; Rojas et al., 2018) and shorter survival (Meeter et al., 2018; van der Ende et al., 2019; Benussi et al., 2020; Cajanus et al., 2020), suggesting the utility of an early NfL assessment in the prediction of future disease aggressiveness.