CCR2 and neoplasm: Chemokine receptors play critical roles in tumor growth, metastasis, and immune suppression (151), Several fluorinated chemokine receptor antagonists have been developed, targeting CCR2 (152), CCR4 (153), CCR5 (154), CXCR1 (155), CXCR2 (156), and CXCR4 (157, 158), effectively blocking immune cell trafficking that promotes tumor growth.