CD68 and rectal cancer: MCP-1, encoded by the gene CCL2, and MIP-1B, encoded by the gene CCL4, are both chemokines involved in the recruitment and differentiation of macrophages: a study conducted on colon-rectal cancer patients correlates CCL4 with the differentiation of monocytes in M2 macrophages, while CCL2 is already correlated with the infiltration degree of macrophages CD68-positive [61].