 Although, this was the first time that the T cell receptor was used for gene therapy, it was not the first time that gene therapy was used in cancer.Tumor cells modified with a gene for immune growth factors such as GM-CSF, had been used many years previously and continue to be used, although the efficacy of GM-CSF modified tumor lines as a cancer vaccine remain extremely modest, at best.There has been some debate as to the role of the T cells in treating the cancer in these studies as high-dose IL-2 and chemotherapy have also been shown to have anti-cancer properties.