Interestingly, intracellular strains induced a strong IL-8 and TNF-α secretion from early times of infection compared with the other pathotypes (except EAEC infection at 4 h), which correlates to the strong NF-κB activation and the intestinal pathology caused by these pathotypes, in spite of the inhibitory effects observed in ERK1/2 phosphorylation. Here, NFKB1 is linked to infection.