NEFL and amyotrophic lateral sclerosis: On comparing ALS and control groups, significant elevations of biomarker concentrations in the ALS group were reproduced for CSF TDP‐43 (P = 0.0087, Fig. 3B), plasma NfL (P = 0.0031, Fig. 3C), and CSF NfL (P < 0.0001, Fig. 3D), while neither plasma TDP‐43 nor plasma t‐tau levels were different between the groups, in contrast to those in the discovery cohort.