CCL2 and neoplasm: As expected, the analysis of monocyte-macrophage system-associated cytokines showed that macrophage chemotaxis-related protein CCL2 and MIF were upregulated in the tumor diameter ≥3 cm group (Student’s t-test, CCL2, p = 0.0285; MIF, p = 0.0105), whereas the M1 polarization-related factors IFN-γ and TNF-α were downregulated in the tumor diameter ≥3 cm group (Student’s t-test, IFN-γ, p = 0.0041; TNF-α, p = 0.0104), indicating that macrophages were recruited more; conversely, the polarization of anti-tumor M1 macrophages was restricted (Figure 6E).