In a prospective controlled trial 364 canine malignant melanoma patients received after complete or partial surgery: (i) a combined treatment that involves intra/peri-tumoral injection of lipoplexes containing the HSV-tk/r suicide gene, ganciclovir, canine interferon-β gene and bleomycin intra and/or (ii) a subcutaneous vaccine composed by canine melanoma cell extract and lipoplexes containing hIL-2 and hGM-CSF genes [68]. This evidence concerns the gene TKT and melanoma.