CD14 and acute myeloid leukemia: Circulating M-MDSC frequencies of AML were significantly higher than those of HC both in CD14+ monocytes (46.22% ± 2.95% vs. 1.07% ± 0.17%, p < 0.01) and peripheral blood mononuclear cells (PBMCs) (4.21% ± 0.80% vs. 0.17% ± 0.03%, p < 0.01).