Description
CD40 protein is expressed on all B-lymphocytes during various stages of development, activated T- cells and monocytes, follicular dendritic cells, thymic epithelial cells, and various carcinoma cell lines. It is expressed on most mature B-cell malignancies and on some early B-cell acute lymphocytic leukemias. Human CD40 has been found to be the receptor for a protein involved in an X- linked immunodeficiency syndrome. The CD40 ligand is identical with a T-cell restricted cell surface activation antigen designated 5c8. The mouse ligand of CD40 is gp39.Based on its homology with other members of the TNF ligand protein superfamily the protein is referred to also as TNFSF5