The majority of HTLV-1 Env- and Tax-specific CD4⁺ T cells are not infected with HTLV-1.

This figure shows concomitant detection of intracellular Tax and IFN-γ expression in CD4⁺ T cells after 6 hours in vitro activation with peptides from a patient with HAM/TSP (TAF). Dot plots showed that the vast majority of Tax⁺cells came from the IFN-γ⁻ fraction. This was representative of experiments on 5 different subjects; refer to Table 1.