In contrast, a higher expression of MCP-1 by HCs in comparison to ALS patients was detected after stimulation with HERV-K env 19–37 peptide (ALS vs. HCs, mean ± SD = 0.673 ± 0.124 vs. 1.33 ± 0.539; p = 0.021) (Figure 3d) whereas no difference in MCP-1 expression was observed after HERV-K env 109–126 stimulation (Figure 3d). Here, CCL2 is linked to amyotrophic lateral sclerosis.