Comparison of surface expression of CD27 and CD127 on FOXP3⁺CD4 T cells in tumors versus peripheral blood from the same patients. Tumor digests and peripheral blood from patients were thawed and immediately stained with anti-CD3, anti-CD8, and anti-FOXP3 mAb along with either (A) anti-CD27 or (B) anti-CD127 mAbs. The dotplots were gated on CD3CD4 (CD3⁺CD8⁻) T cells. The numbers represent the percentages of CD4 T cells in each quadrant. These results are representative of multiple independent experiments using tumor digest (n = 19) and PBLs (n = 9) samples from the same patients with metastatic melanoma.