CD4

CD4 is a single chain transmembraneous glycoprotein (59 kDa) which belongs to the immunoglobulin superfamily. The CD4 antigen is expressed on a T cell subset (helper/inducer) representing 45 percent of peripheral blood lymphocytes and at a lower level on monocytes. Most cases of cutaneous T cell lymphoma, including mycosis fungoides, express the CD4 antigen and HTLV-1 associated adult T cell leukemia/lymphoma is also generally CD4 positive.

Note: the use of 1 percent or greater H₂O₂ to block endogenous peroxidase has a detrimental effect on the epitope recognized by clone 1F6. Therefore, it is recommended that endogenous peroxidase is blocked before retrieval with 0.5 percent H₂O₂ /methanol for 10 minutes, otherwise staining intensity may be reduced