Multivariate analysis identified that factors associated with poor OS included elevated neutrophil count, increased monocyte count, decreased hemoglobin (HB) levels, elevated lactate dehydrogenase (LDH), increased β2-microglobulin (β2-MG), and peripheral blood blast count ≥5% (<i>p</i> < 0.05), while the decreased HB and peripheral blood blast count ≥5% was independent adverse prognostic factors for OS.<h4>Conclusion</h4>CMML is a highly heterogeneous disease with generally unfavorable clinical outcomes. The gene discussed is HLA-G; the disease is chronic myelomonocytic leukemia.