HAVCR2 and leukemia: T cell immunoglobulin and mucin-domain containing-3 (TIM-3) acts as inhibitory costimulatory molecules in T cells.22 AML blasts present TIM-3 as a marker of exhausted T cells.20,23 We only partially understand how it functions in leukemia cells and it is likely complicated.20 In the bone marrow and peripheral blood of AML patients, exhausted T cells have different phenotypes between subsets.23 Li et al have reported that CD4∗ and CD8∗ T cells from recently diagnosed AML patients express more TIM-3 than those from normal controls.