CD4 and neoplasm: Next, to determine whether tumor restriction was antigen-dependent, activated OT-II cells were transferred into B16-GP bearing mice on Day 8 after tumor inoculation, the transferred activated OT-II T cells did not show any effect on B16-GP tumor metastasis (Figures 1C, D), indicating that anti-tumor activity was mediated by SMARTA cells after CD4+ T-cell transfer, and not by unrelated CD4+ T cells.