In contrast, Lee et al. [17] report that IL-8 mRNA levels were elevated in milk somatic cells (MSC) after artificial intramammary infection with E. coli and S. aureus, with a faster and stronger inflammatory response to E. coli infection observed (75-fold increase after 16 h) compared to S. aureus (29-fold increase after 24 h). This evidence concerns the gene CXCL8 and infection.