Our data suggests that an infection with E. coli O157:H7 (Stx−) is capable of modulating the immune response causing dramatic decreases in CCL20. A similar trend was observed in a bacterial infection with Mycoplasma gallisepticum in chicken, where a down-regulation in mRNA expression of CCL20 as well as of IL-1, IL-8 and IL-12p40 genes was seen. Here, CCL20 is linked to bacterial infectious disease.