In their large cohort of FTD patients [n = 361, actually including also patients with corticobasal syndrome (CBS) and progressive supranuclear palsy (PSP), which belong to the spectrum of FTLD syndromes], Meeter et al. (2018b) demonstrated that each clinical form of FTD had higher CSF NFL levels compared with neurologically healthy controls, with the highest levels found in FTD-MND. This evidence concerns the gene NEFL and frontotemporal dementia.