CCL2 and granulomatosis with polyangiitis: In this study, we demonstrated that PR3-ANCA serum from WG patients up-regulated the expression of various TLRs and NODs in human PBMCs (Fig. 1) and primed PBMCs to produce proinflammatory cytokines such as IL-6, IL-8, MCP-1, and TNF-α via TLRs and NODs (Figs. 2 and 3).