The samples with high NK cell percentage exhibited increased expression of HLA-E on both CD34+ leukemic blasts as well as on the total leukemic blast population (Figures 1B, C), suggesting that despite a high percentage of mature NK cells, the killing of leukemic blast targets by NK cells may be blocked by inhibitory HLA-E expression on the AML tumor cells. This evidence concerns the gene HLA-E and neoplasm.