CCR2 and neoplasm: In the context of liver carcinogenesis monocytes/macrophages exert dualistic functions in a stage-dependent manner with CCR2+ CCL2-responsive monocytes promoting tumor surveillance through the elimination of senescent premalignant hepatocytes in healthy livers (Figure 4), whereas in established tumors monocytes/macrophages are reprogrammed to silence NK cells resulting in tumor growth (227, 228).