NEFL and amyotrophic lateral sclerosis: Consistent with previous reports, plasma concentrations of Nf‐L and Nf‐H proteins were increased among ALS patients compared to HC‐1 (p < 0.0001; Fig. 2A and B) and significantly elevated in ALS‐F and ALS‐S compared to HC‐1 (p < 0.0001 and p = 0.0014; Fig. 2A).8, 25