HBZ and tropical spastic paraparesis: The antibody response to NY-ESO-1 did not correlate with tax and HBZ mRNA expression; moreover, the antibody response to NY-ESO-1 did not correlate with the PVL in any of the test groups (i.e., ATL, HAM/TSP and ACs) (Table 1 and Additional file 2 Figure S2), suggesting that virological status in HTLV-1-infected individuals does not affect the NY-ESO-1-specific immune responses.