CD4 and acute myeloid leukemia: In 2016, Yaxian Kong had reported that TIGIT expression elevated in the PB CD8+ T cells of AML patients, and high TIGIT was associated with poor clinical outcome in AML (49); however, we only found higher expression of TIGIT on PB CD4+ T cells of DN AML patients compared with HIs in the younger age group and on PB CD8+ T cells in both young and older patients.