CCL2 and infection: MCP-1 serum levels were decreased in mutant mice at early infection as also observed for lung levels in all mutant mice, but at 4 weeks infection they were increased in memTNFΔ1–12 KI and TNF−/− mice but not in memTNFΔ1–9,K11E KI mice compared to wild-type mice, suggesting an enhanced activity of lung macrophages (Fig. 3G, H).