In serum, mean NfL levels were 6.1-fold higher in ALS (n = 30) (217.2 pg/mL ± 154.6 pg/mL) as compared to HC (n = 20) (35.35 pg/mL ± 25.93 pg/mL), which was statistically significant (p < 0.0001, Cohen’s d = 1.50) and expected based on prior studies (Figure 5A). Here, NEFL is linked to amyotrophic lateral sclerosis.