Studies have uncovered abnormalities in peripheral blood cells (including leukocytes, CD4+ T cells, CD8+ T cells, natural killer T cells, Th17 cells, regulatory T cells, and monocytes) and immune proteins (such as immunoglobulins, complement factors, cytokines, and chemokines) in ALS patients or animal models (6). The gene discussed is CD4; the disease is amyotrophic lateral sclerosis.