Association between frequencies of CD4⁺ Tregs and patient response to therapy. (A) Nonparametric analysis of the relationship between doses of IL-2 administrated and percentages or absolute cell count of Tregs from week-1 PBMCs in 3 NMA trials. Spearman r and P values are shown. (B) The percentages of Tregs in CD3⁺ T cells and absolute Treg counts of week-1 samples from nonresponders and responders in 3 NMA TIL trials are shown. Horizontal bars represent the median values. (C) The percentages of CD4⁺ Tregs as a percentage of total CD4⁺ T cells in week-1 samples and absolute CD4⁺ T-cell counts in the peripheral blood of nonresponders (NR) and responders (R) in the 3 NMA TIL trials are shown. (D) Ratio of CD4⁺ Tregs to total CD8⁺ T cells in week-1 samples and absolute CD8⁺ T-cell counts in the peripheral blood of nonresponders and responders in the 3 NMA TIL trials are shown.