Correlation between FoxP3 expression, Tax expression, and proviral load. (A) The percentage of FoxP3 expression in CD4⁺Tax⁻ cells was correlated with the percentage of CD4⁺Tax⁺ cells both in ACs (N = 23) and in HAM/TSP patients (N = 22). The P values were calculated by a 2-tailed Spearman test. (B) The proviral load was correlated with the level of FoxP3 mRNA expression in CD4⁺ cells (measured by Q-PCR) both in ACs (N = 11) and in patients with HAM/TSP (N = 13).