For NF-L levels in plasma samples, Mann–Whitney test also indicated significant differences (MW = 28, P = 0.000), showing a significant increase when comparing plasma levels in amyotrophic lateral sclerosis cases (86.00 ± 12.23 pg/mL) to HC cases (12.69 ± 1.15 pg/mL; P = 0.000; Fig. 2B). Here, NEFL is linked to amyotrophic lateral sclerosis.