HD increased regulatory T cells, decreased CD4- CD8- T cells, and causes a biphasic course with either a transient decline (natural killer T cells, CD8+ HLA-DR+ T lymphocytes, activation of the complement system, and higher concentration of TGFβ) or a transient increase (CD4+ T lymphocytes, CD4+ HLA-DR+ T lymphocytes). This evidence concerns the gene CD4 and Huntington disease.