PBMCs activation against the selected HERV-K env peptides (HERV-K env 19–37 and HERV-K env 109–126) was assessed in ALS patients and HCs analyzing the percentage of CD4+ cells secreting IFN-γ, TNF-α, MIP-1 α, and MCP-1. This evidence concerns the gene CCL2 and amyotrophic lateral sclerosis.