The enrichment of Tregs in the tumor seems to be driven by the expression of the chemokine receptors CCR4 and CCR7 that drives their migration and also the chemo attractants such as monocyte chemotactic protein-1 (MCP-1) also known as CCL2 and C-C chemokine ligand 22 (CCL22) (28). This evidence concerns the gene CCR4 and neoplasm.