MDSCs respond to the stimulation of cancer-derived factors, such as granulocyte colony-stimulating factor (G-CSF), interleukin-6 (IL-6) and granulocyte monocyte colony-stimulating factor (GM-CSF), through transcription factors STAT1, STAT3, STAT6 and NF-κB to proliferate and obtain immunosuppressive activity in bone marrow [8, 9]. The gene discussed is CSF3; the disease is cancer.