Increased NfL levels therefore might be related to spinocerebellar tract (and possibly brainstem) degeneration in SCA3, rather than, e.g., corticospinal tract degeneration (as, e.g., in ALS (Menke et al, 2015; Skillback et al, 2014)), as suggested by our human neuropathological findings. This evidence concerns the gene NEFL and amyotrophic lateral sclerosis.