CSF pNFH had the highest AUC (AUC: 0.874; 0.803–0.944) (J: 7623 pg/mL, sensitivity: 82.7%, specificity: 83.3%, LR + : 4.96, LR−: 0.21, p < 0.0001) (Fig. 2D), followed by plasma NFL concentration (AUC: 0.833; 0.756–0.910) (J: 95.42 pg/mL, sensitivity: 76.4%, specificity: 83.3%, LR + : 4.59, LR−: 0.28, p < 0.0001) (Fig. 2F) and CSF NFL (AUC: 0.805; 0.719–0.891) (J: 2532.5 pg/mL, sensitivity: 80.3%, specificity: 81.8%, LR + : 4.41, LR−: 0.24, p < 0.0001) (Fig. 2B) when comparing patients with ALS to ALS mimics . Here, NEFL is linked to amyotrophic lateral sclerosis.