Mouse models of neurodegenerative diseases, including Huntington's disease (Soylu-Kucharz et al., 2017) and SCA3 (Wilke et al., 2020b; Garcia-Moreno et al., 2022; Jansen-West et al., 2022; Haas et al., 2022; Lin et al., 2022; Costa et al., 2020), have been shown to exhibit NfL changes similar to those seen in patients. This evidence concerns the gene ATXN3 and juvenile Huntington disease.