CXCL8 and infection: Evidently, IL8 of Caco-2 cells was the most strongly up-regulated among all of the genes examined after WT S. Typhimurium infection (10.083-fold change, S2 Table); however, such upregulation increased more than 2-fold after S. Typhimurium ΔspeG infection (23.865-fold change, S4 Table).