Correlation between FoxP3 expression and the rate of CD8⁺ cell–mediated lysis. The percentage of FoxP3⁺ cells in all CD4⁺ cells (A), the percentage of CD4⁺FoxP3⁺ Tax⁻ cells (B), and the percentage of CD4⁺FoxP3⁺ Tax⁺ cells were plotted against the efficiency of lysis. The data represent the result obtained with samples from 15 ACs and 19 HAM/TSP patients. The P values were determined by a 2-tailed Spearman test. For the percentage of CD4⁺FoxP3⁺ Tax⁺ cells, we have also represented the correlation with the efficiency of lysis on a smaller scale, to clarify the lack of correlation here (C).