The recent finding of a positive correlation between neurofilament light chain level in cerebrospinal fluid and disease progression rate in progressive supranuclear palsy, Alzheimer’s disease, dementia with Lewy bodies and frontotemporal lobar degeneration [1, 56] is a promising start to understand the underlying pathophysiology, and to identify accurate biomarkers and genetic modifiers of rapid progressors in neurodegenerative diseases such as fulminant CBD. This evidence concerns the gene NEFL and neurodegenerative disease.