CD4 and colonic neoplasm: MSCs produce CCL3, -4 and 5 and promote metastasis when mixed with breast and colon cancer cells; CD4+ Foxp3+ Tregs preferentially express CCR5 when compared with CD4+ Foxp3− effector T cells; and TAK-779-mediated inhibition reduces Treg migration to tumors, reducing pancreatic tumor size [47] Even the absence of CCR5 ligands is associated with reduced infiltration of antigen-specific T cells and associated metastasis.