NEFL and proximal spinal muscular atrophy: In this case, the linear regression model adjusted for age and sex did not show significant differences in plasma NF-L levels between the healthy control samples (control: 13.93 ± 1.34 pg/mL) and the non-treated adult SMA patient samples (SMA(Pre): 10.37 ± 1.11 pg/mL) due to the group effect [F(1,55) = 0.481, p = 0.491].