Importantly, the most dramatic effect was seen in the tumor microenvironment as the absolute number of OT-II CD4+FoxP3.gfp+ T cells, assessed by flow cytometry (Fig. 4E) or confocal microscopy (Fig. 4F,G), were reduced in mice treated with SA-4-1BBL as compared with SA treated controls. This evidence concerns the gene FOXP3 and neoplasm.