CCL2 and polyarteritis nodosa: In agreement with previously published reports [12–14], inflammatory markers involved in the PAN model, including cytokine TNF-α (Fig. 5) and its receptor TNFR1 (Fig. 6), IL-1β (Fig. 7) and chemokine MCP-1 (Fig. 8), were detected by immunohistochemistry and real-time PCR.