CCL3 and infection: This is consistent with overall higher levels of MCP-1 and MIP-1α following infection in preterm lungs and a relatively greater elevation in these mediators compared with uninfected baseline levels (for MCP-1: 4.88-fold increase in preterm compared to 3.26-fold in full-term; for MIP-1α: 9.4-fold increase in preterm compared to 2.7-fold in full-term).