We thus used ARTFL LEFFTDS Longitudinal Frontotemporal Lobar Degeneration (ALLFTD; www.allftd.org) resources and conducted a comprehensive cross-sectional and longitudinal study to evaluate and compare the prognostic, susceptibility/risk and predictive performance of plasma GFAP and NfL in the largest series of well-characterized presymptomatic FTD mutation carriers and participants with FTD syndromes. This evidence concerns the gene GFAP and frontotemporal dementia.