CCL2 and Splenomegaly: Indeed, compared with recipients of IL-23R-sufficient T cells, we observed no difference in splenomegaly (Figure 1D), splenic T cell accumulation (Figure 1E), hepatic infiltrates (Figure 1F), serum concentrations of proinflammatory cytokines and chemokines, such as IL-6, MCP-1, TNF-α, and IFN-γ (Figure S1A available online), or weight loss (Figure S1B) in recipients of Il23r−/− T cells.