FOXP3 and neoplasm: Administration of anti-TGF-β antibody in vitro blocked conversion of Tconv to the Treg phenotype, and in vivo administration of anti-TGF-β antibody in mice implanted with renal cell carcinoma reduced tumor burden, decreased numbers of circulating FOXP3+ CD25+ CD4+ cells in peripheral blood, and removed the immunosuppressive capabilities of FOXP3+ CD25+ CD4+ T cells (283).