It is reported that CCL2 could induce the differentiation of macrophage into protumor phenotypes through CC chemokine receptor 2 (CCR2); In mouse tumor models such as colorectal cancer, prostate cancer, and melanoma, CCL2 recruit TAMs to tumor sites through ligand-receptor interactions with CCR2 or other forms of action (47–50). The gene discussed is CCR2; the disease is colorectal cancer.