CCL2 and hepatocellular carcinoma: To explore the role of the CCL2/CCR2 and CXCL1/CXCR2 axes in primary HCC, expression of CCL2, CCR2, CXCL1, and CXCR2 was evaluated by immunohistochemical analysis of tissue microarrays of tumors from the primary rat HCC model at different time points (Fig. 2A).