CD4 is expressed on thymocyte subsets, it marks helper/inducer T cells, and it is expressed in 55-65% of mature peripheral T cells. Subpopulations of suppressor or cytotoxic T cells can be identified among CD4-positive T cells. CD4 is also expressed on monocytes/macrophages, Langerhans cells and other dendritic cells. CD4 is not expressed on B cells.
Further information and references to relevant literature are available in the products Instructions For Use.