NEFL and neurodegenerative disease: In agreement with the tendency of FTLD-TDP toward higher NFL levels is the demonstration, in the large neuropathological investigation of Olsson et al. (2019), of a correlation between CSF NFL and TDP-43 load in 13 of 17 brain regions in the whole neuropathological cohort (n = 120) encompassing several neurodegenerative diseases.