CD4 and neoplasm: To address the critical issue of whether m1G4 T cells, rather than endogenous CD8 +and CD4+T cells, respond to NY-ESO-1 and can suppress growth of syngeneic tumor cells expressing the full-length human NY-ESO-1 protein, we subcutaneously injected HHD mice with 106 syngeneic tumor cells (MCA induced tumors from HHD mice) expressing NY-ESO-1 (1F4, figure 5).