CD4 and amyotrophic lateral sclerosis: Also, since a significant reduction of regulatory T cells (CD4 + CD25+) and monocytes (CD14+) in blood of sporadic ALS patients with less severe disease was noted [85], suggesting early recruitment of these cells to the CNS areas of neurodegeneration, it is possible that decreased serum IL-2 levels in our ALS patients during disease progression reflects limited guidance of antigen-driven T cell development.