NEFL and amyotrophic lateral sclerosis: Thus, we measured the CSF levels of NfL, pNfH, UCHL1, Aβ1–40, and Aβ1–42 with ELLA and ELISA at baseline, as well as 3 and 6 months after tofersen initiation in 8 of the 9 individuals of our exploratory cohort (for 1 patient, samples from the additional timepoint of 6 months were not available) plus 14 additional SOD1‐ALS patients from the previously described German trial5 (n = 22 patients in total; Fig. 3A).