Although renal macrophages from pcDNA3.1-treated lupus mice exhibited enhanced mRNA levels of TNF-α, IL-1β, IL-6, IL-10, MCP-1 and Nos2, macrophages from pGRN-treated mice showed much higher expression levels of TNF-α, IL-1β, IL-6, IL-10, MCP-1 and Nos2, slightly higher IL-12 and no significant changes in the expression of Arg1 (Fig. 3A), suggesting that up-regulated expression of GRN promoted renal macrophages toward M2b differentiation induced by ALD-DNA. Here, ARG1 is linked to systemic lupus erythematosus.