For example, local treatment of murine H22 HCC ectopic tumors by injection of naked plasmids expressing the co-stimulatory molecules 4-1BBL and sPD-1 eradicated a small number of pre-existing tumor cells in murine tumors and larger amounts of pre-existing tumor cells in approximately 60% of mice (105). This evidence concerns the gene HOXD13 and hepatocellular carcinoma.