CD44

The monoclonal antibody is directed against the CD44- antigen, which is mainly expressed on leucocytes and erythrocytes. Very few types of tissue or cells lack CD44. Cells and tissues that lack CD44 include platelets, hepatocytes, certain lymphoid cell lines, cardiac muscle, kidney tubular epithelium, testis and portions of the skin. The CD44 antigen is present on approximately 90% of lymphocytes, monocytes, and granulocytes and in lower amounts on thymocytes, fibroblasts, and erythrocytes.
The antigen mediates a variety of functions, including leucocyte–endothelial cell binding and lymphocyte homing to certain peripheral lymphoid microenvironments.