FoxP3 expression in HTLV-1–seropositive subjects. (A) FoxP3 expression in CD4⁺ cells in 7 uninfected subjects, 28 ACs, and 30 HAM/TSP patients gated on the CD4⁺. The P value was calculated by an unpaired t test (2-tailed). (B) Dot plot showing FoxP3 and CD127 expression in PBMCs, gated on the CD4⁺ population, from a representative HAM/TSP patient. (C) Time course of FoxP3 expression in CD4⁺ cells, for 4 different ACs and 4 HAM/TSP patients.