The presence of chemokine C-C motif ligand 2 (CCL-2), or monocyte chemoattractant protein 1 (MCP-1), in the TME, produced by both tumour cells and stromal cells, has been shown to attract macrophages and subsequently maintain chemotaxis by stimulating these macrophages to also secrete CCL-2 [11]. The gene discussed is CCL2; the disease is neoplasm.