The ALS patients showed an increased Abs presence against the TDP-43(398–411) epitope (Figure 1C), with a positivity measured in 51.11% of the ALS group versus 4.44% of HCs with a Fisher’s exact test p < 0.0001 (Mann–Whitney U test, p < 0.0001, HCs median = 0.11, 95% CI [0.074, 0.168], ALS median = 0.386, 95% CI [0.332, 0.453]; cut off value of 0.385; and AUC = 0.915). This evidence concerns the gene TARDBP and amyotrophic lateral sclerosis.