CXCL12 and infection: To further characterize the impact of early infection on the mucosal cytokine/chemokine network, we investigated the expression of 13 chemokines (CCL2, CCL3, CCL4, CCL5, CCL11, CCL19, CCL20, CCL21, CCL25, CCL28, CXCL8, CXCL10, and CXCL12) using real-time quantitative RT-PCR.