FIG. 3.

Correlation between frequency of single-cytokine-positive, HTLV-1-specific CD4⁺ T cells and proviral load (PL). There is a significant positive correlation between IL-2-positive HTLV-1-specific CD4⁺ T-cell frequency and proviral load in ACs. There is a trend toward a positive correlation for all three cytokines in ACs, but this does not reach significance for IFN-γ and TNF-α. Data were analyzed by Spearman rank correlation. The solid line represents a least-squares regression line. The asterisk indicates a significant correlation.