CD40L or CD154 is a membrane glycoprotein and differentiation antigen expressed on the surface of T-cells。 The CD40 ligand stimulates B-cell proliferation and secretion of all immunoglobulin isotypes in the presence of cytokines 。 CD40 ligand has been shown to induce cytokine production and tumoricidal activity in peripheral blood monocytes。 It also costimulates proliferation of activated T-cells and this is accompanied by the production of IFN-gamma ,TNF-alpha ,and IL2 。