Moreover, neutrophils can cooperate with metastatic tumor cells to enhance both the dissemination of tumor cells out of the primary tumor and their subsequent intravasation into the lung vasculature through the secretion of G-CSF to attract neutrophils, which suppress NK cell activity through ROS signaling and shield intraluminal metastatic tumor cells from being cleared by NK cells (Figure 2), and ultimately enhance metastatic outgrowth [109,110]. Here, CSF3 is linked to neoplasm.