TNF and neoplasm: In addition, the concentrations of IFN-γ, GM-CSF, and TNF-α in the peripheral blood of patients with stage IV colorectal cancer showed an increasing trend (one-way ANOVA, GM-CSF control vs stage IV, p = 0.0176; TNF-α stage II vs stage IV, p = 0.0378), suggesting a possible restoration of M1 macrophage-mediated anti-tumor function in colorectal cancer patients with distant metastases.