CD8A and neoplasm: In addition, in contrast to selecting a purified population of MHC-I restricted OT-I cells, the FIH knockout is present in all T cell subsets in the orthotopic model, with different contributions from effector (e.g., CD8+ T cells) and suppressor populations (e.g., CD4+ regulatory T cells); these other cell types may thus be influencing overall anti-tumour outcomes.