Previous studies have shown that interaction of tumour cell-associated CD40 with CD40L can lead to different consequences: (i) CD40 triggering induces upregulation of HLA and adhesion molecules on the surface of tumour cells (Ahmad and Shi, 2000), thus enhancing their immunogenicity, and (ii) exposure of neoplastic cells to soluble CD40L results into inhibition of cell proliferation and induction of cell death by apoptosis (Hirano et al, 1999; Ghamande et al, 2001; Bugajska et al, 2002; Szocinski et al, 2002). This evidence concerns the gene CD40LG and neoplasm.