CD8A and neoplasm: Similarly, in mice bearing CT26 tumors, independent depletion of NK cells, CD8 T cells or CD4 T cells did not completely abrogate anti-tumor efficacy (9% (P > 0.337), 11% (P = 0.303), 42% (P < 0.001) GRI vs. vehicle control in CD4 depleted mice (Fig 5F)).