FOXP3 expression in single- and dual-specific peripheral-blood T cells. (A) FOXP3 mRNA and (B) protein levels in CD4⁺, single Vα⁺, and Vα2⁺Vα12⁺ PBLs (n = 8; mean ± SD). (C) A representative example of intracellular FOXP3 staining in isolated Vα2⁺ cells also expressing Vα12 (n = 8) and (D) of the frequency of dual-specific Vα12⁺ cells within the CD4⁺FOXP3^– and CD4⁺FOXP3⁺ subsets of isolated Va2⁺ cells (n = 4). *P < .05, ***P < .001; ns indicates not significant.