CCL2 and bone metastasis: Additionally, EP4 antagonists can suppress proinflammatory cytokines (e.g., C-C motif chemokine ligand 2 [CCL2], IL-6, and C-X-C chemokine motif 8 [CXCL8]), reduce inflammation-dependent bone metastasis, and diminish immunosuppression, while restoring antitumor immunity (91, –93).