To determine if EHEC-Hly and EspP could theoretically come into direct contact during infection, we studied the chronology of EHEC-hlyA and espP expression in four selected EHEC strains producing EHEC-Hly together with EspPα (O157 : H7 strain EDL933 and O26 : H11 strain 5236/96) or EspPβ (O6 : HNT strain 3503/98 and O163 : H19 strain 36/03; Table 1) under laboratory and in vivo mimicking conditions. Here, KRCC1 is linked to infection.