The effect of tofersen on neurofilament levels drove its recent accelerated approval for a specific form of amyotrophic lateral sclerosis, with the expectation that neurofilament reduction will ultimately lead to clinical benefit (https://Www.Fda.Gov/Drugs/News-Events-Human-Drugs/Fda-Approves-Treatment-Amyotrophic-Lateral-Sclerosis-Associated-Mutation-Sod1-Gene). Here, SOD1 is linked to amyotrophic lateral sclerosis.