Peripheral blood T-cell analysis. T cells in the peripheral blood were analyzed by flow cytometry at days 28, 100, 180, and 365 after transplant. (A) Representative gating strategy. (B) Comparison of CD4⁺, CD8⁺, and CD4⁺CD25⁺CD127^low Tregs in SOC and PTCy+Aba treatment groups across time points. (C) T-cell activation was assessed by measuring HLA-DR upregulation. Representative examples shown for 1 patient each in the SOC and PTCy+Aba groups at day 100 after transplant. (D) Comparison of T-cell activation as indicated by HLA-DR expression in SOC and PTCy+Aba treatment groups across time points.