Li et al. demonstrated that G-CSF was amplified in host NK cell-deficient mice and that TANs suppressed the spread of breast tumor cells in the lung, while in mice with active NK cells, TANs promoted metastasis.108 They found that ROS produced by neutrophils not only inhibit the antitumor activity of NK cells but also kill tumor cells.108 Therefore, the ROS generated by TANs represent a double-edged sword, with their specific impact on tumors depending on the composition of the TME and the immune evasion capabilities of tumor cells. The gene discussed is CSF3; the disease is neoplasm.