Due to the role of functional CD40 and IL-18 polymorphisms in acute rejection and taking into account the importance of IL-18 and CD40 in T cell activation and important role of T cell activation in allograft rejection, we conducted this study to investigate the association of SNPs in the genes of IL-18 and CD40 with allograft function in liver transplant recipients. The gene discussed is CD40; the disease is digestive system neoplasm.