It should be noted nevertheless that splenic T cells isolatedfrom mice treated with both IL-2 secreting cells and pioglitazone showed noincrease in response as compared with the spleen cells isolated from animalstreated with IL-2 secreting fibroblasts alone as measured by the ELISPOT IFN-γ assay.These results suggest that the tendency of pioglitatzone to increase themean survival time in mice bearing a glioma is not due to an increase insystemically driven T cell immunity against the Gl261 cells. This evidence concerns the gene IFNG and glioma.