TIGIT and acute myeloid leukemia: Taken together, in addition to the previously reported high expression of PD-1 and co-expression of PD-1 and TIGIT in the PB of DN AML patients and increased PD-1 expression in the BM of DN AML patients, we further identified the accumulation of TIGIT+ CD8+ T cells in the BM of DN, CR, and R/R patients.