CD73+ CD8 T cells are more functional, and high frequency of this subpopulation associates with low disease burden in AML, whereas CD73− CD8 T cells exhibit features of exhaustion manifested by high expression of inhibitory receptors such as PD-1 and TIGIT, increased intracellular expression of Eomes, and reduced capacity of cytokine production and high susceptibility to apoptosis. The gene discussed is TIGIT; the disease is acute myeloid leukemia.